How is the system recovered in the event of the following:

1. Communication Failures
 In the case of a communications failure, persistent messages
remain on queues until they are removed by a receiving
application. If the message is being transmitted, it remains
on the transmission queue until it can be successfully
transmitted. To recover from a communications failure, you can
usually restart the channels using the link that failed.
In the event of a network outage, redundant networks can be
used to ensure network availability if they are properly
constructed. Redundancy makes sure that if one network route
fails, the other will take over without interruption. In
particular, if the network paths are dispersed geographically,
this method of high availability is efficient. In the case of
a communications breakdown, backups can be used to quickly
restore the system. Either a complete system restore or a
file-and-folder restoration can be used for this.
Always keep the backup in a safe location, ideally offsite. To
successfully recover, network performance must also be
improved. Performance issues can be found and fixed via
network monitoring and logging. Additionally, distinct
networks for various types of traffic can be built via network
segmentation. By regulating traffic flow and isolating high-
traffic zones, this can enhance performance.

2. Network Card
Some Procedure:
 Update network card drivers
 To do this we have to go to Start, write Device Manager ,
click on Network Adapters, look for the specific card and

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 click the second mouse button. Once this is done, the
option to update will appear.

 Disable and re-enable the card

 Following a bit the thread of what we mentioned earlier,
this time we are going to disable the card to re-enable
it. What this basically does is to recognize the network
card again.
We have to go to Device Manager again and follow the
steps we mentioned, but this time we are not going to
update, but to Disable device and later re-enable it.
 Update Windows
 Another step that we must take or make sure that we have
done it is to update Windows . Having the latest version
of the operating system will be very important so that
everything works correctly and of course so that it
recognizes the network card and other devices.

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  Restore your computer to a previous state
 We have to go to Start, we enter the Control Panel, we go
to Recovery and System Restore. There we give Next and we
return to a previous point in which the equipment was
working correctly before having made any changes.

3.  Local LAN component (e.g., a hub, router, or switch)

 Reboot your computer, router, and even your switch.
 Change any settings and uninstall any programs you got after
it stopped working, no matter how unrelated they seem, the may
have caused the issues. Files like Office documents and
pictures are not causing the issue.
 Check to make sure all cables are secure and that all lights
that are normally lit are currently lit. If that doesn't work,
reset the router. Make sure you test the connection with three
different websites, in case one is down.

4. Firewall Failure
 To troubleshoot and fix Windows Firewall problems, use
the following steps:

Step 1: Download the Windows Firewall Troubleshooter

from Microsoft (opens in new tab).
Step 2: Double-click the WindowsFirewall.diagcab file.

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 Step 3: Click Next.

Step 4: Depending on the troubleshooter result, click

the option that will fix the problem.

Step 5: If everything is working as expected, then click

Close the troubleshooter.
 If you stumble upon any of these or similar issues, there are
several things you can do. You can use the "Windows Firewall
Troubleshooter," which is an automated tool that scans and
fixes common problems. It's also possible to reset the
firewall settings to defaults, and you can manually allow
blocked apps through the Windows Firewall.

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 5. Mail Server failure
 Perform a full backup of server - Before the initiation
of any attempts at recovery, it is imperative that a full
backup first be performed on the affected server. An
experienced administrator will know that the race to
solve the problem might sometimes cause more harm as a
direct results of mistakes made. Moreover, the
installation of patches or updates that causes
inadvertent problem may also not be easy (or even
impossible) to reverse.
 Initiate recovery - Only after the creation of a backup
should the recovery of a failed Exchange Server be
initiated. Below is a short list of common problems.
 Boot failure: Assuming that the boot failure is not
caused by a malware attack, initiate the Recovery
Console by hitting the F8 key as the boot loader is
being loaded. Problems related to errant system
services or problematic applications in the startup
queue may be resolved here.
 Disk failure: Where RAID is used, a recovery here
may be as easy as replacing a failed disk in the
array and waiting for it to rebuild.
 Database corruption: The steps for partial or
complete database corruption may vary, as with the
tools that can be used.
 Configuration problem: While easy to resolve in the
hands of an experienced Exchange administrator, it
can also result in larger problems being caused by
consecutive or multiple configuration mistakes.
 Preparing for easy recovery - An alternative for
businesses that cannot afford failover hardware is to

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 ensure the presence of sufficient storage space to
facilitate the creation of server backups mentioned
earlier. Another way to be prepared would be to ensure
that the Exchange Server environment is properly
documented. Some of the information that should be
documented includes the server name, version of Windows,
version of Exchange Server, database names, location and
size of databases.

6. Web Server failure

 Restoring the server from a backup - If a backup is
available, using the manufacturer's installation disc to
restore from an external backup is your best option for
recovering your server. From the backup you select, the
restoration will restore server settings and directories.
Only the settings must be set up, and any backup-created
data must be restored.
 Resetting the server to factory default settings - All
current settings and installed programs are erased when
you restore your server by restoring it to factory
default settings, therefore you must configure your
server from scratch. Your server resumes after a factory
reset.
 Repair the system drive - The first step in server
restoration is to restore or repair the server system
drive. After you restore the system drive, you will do
whatever is needed to restore the data drives on the
server and restore any sharing that was lost in the
restore.
 Reset your server from a client computer using the
recovery DVD - you can start the server from a bootable

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 USB flash drive that you create, and then you recover the
server from a client computer by using the recovery DVD
that you received from the server manufacturer. The
client computer must be on the same network as the
server.
7. Application Server failure
Step 1: Close all currently running computer applications
by clicking the red "X" in the upper right-hand corner of
the program's window.

Step 2: Windows Start Menu. Press the "Start Menu" button

and click on the "Control Panel" option. This will open a
new window.

Step 3: Windows Control Panel. Click on the text field in the

upper right-hand corner of the "Control Panel." Type
"solution"--this will bring up one or more clickable options;
click on the option labeled "Problem Reports and Solutions."
This will open another new window.

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 Step 4: Windows Problem Reports and Solutions Click on "See
Problems to Check," located on the upper left-hand side of the
"Problem Reports and Solutions" window.

8. Database Sever

 There are multiple reasons for connection failures from

Database to Application server, each may behave differently:
 For network-related issues, Application can restore the
connection with database without any system restart.
 For any connection failure situations, application server
keeps polling the connections and may increase the
overhead or congestion on the application server
resources. There are also situations where few sessions
are inactive, which are waiting to get a response from
database. To ensure everything to be clean, it is
recommended to restart the application server and have
them initialized during server startup.
 If you know your downtime for database server, stop the
application server and then bring down the database

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 server. Later, when you are done, you should bring the DB
server up then the app server.

9. AN Linkage Outage
 Users may experience a lack of connectivity, sluggish data
transfer rates, and other communication issues as a result of
the AN linkage outage.

Steps to solve AN Linkage Outage:

Step 1: Determine the cause of the issue by looking at the
network logs, keeping an eye on network performance, and
scanning for error messages.
Step 2: Isolate the affected locations, once the issue's root
cause has been located, isolate the impacted areas to stop it
from spreading to other network nodes.
Step 3: Restore network connectivity by restarting any
routers, switches, or other networking devices that may have
contributed to the problem.
Step 4: If the problem continues, check for hardware failure
by assessing the equipment's condition and replacing any
damaged components.
Step 5: Update network settings, if a configuration error led
to the problem, update the network configuration and make sure
it is accurate.
Step 6: Once the network connectivity has been restored, keep
an eye on the network to make sure the problem doesn't come up
again.

10.WAN Component Failure

 For deployments that have network partition detection and/or

auto-reconnect disabled, to recover from a network outage:
 Decide which applications and cache servers to restart,
based on the architecture of the cluster. Assume that any

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 process other than a data source is bad and needs
restarting. For example, if an outside data feed is
coming in to one member, which then redistributes to all
the others, you can leave that process running and
restart the other members.
 Shut down all the processes that need restarting.
 Restart them in the usual order.

11.ISP Failure

 In simple terms, the internet is what allows you to

connect to other devices and online services — the
internet allows you to browse the web or send and receive
emails. Wi-Fi enables you to connect to the internet
through a wireless signal.
 Check Wi-Fi router lights — green is good, while red
or orange may indicate that something is wrong with
your Wi-Fi.
 Reboot your router and modem (the classic, “turn it
off and turn it on again” method)
 Reset your router to the factory settings
 Use your computer or device’s network diagnostic
tools
 Forget and re-add Wi-Fi network on your devices
 Reset network settings on your devices
 While there may be a larger problem that is affecting
your internet connection, checking your Wi-Fi can be a
good place to start, and may even be recommended by your
ISP.

12. Component Hardware failure

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  These steps will help you to resolve hardware issues:
1: Checking the Hard Drives - Try to identify bad
sectors. Bad sectors are sectors on a hard drive that can
no longer be used. This may be due to permanent damage or
the inability of the OS to access them. If you find your
system freezing, getting stop errors, or other errors
this may be due to bad sectors. Use chkdsk and repair
these problems.
2: Checking the Power Supply - Check that the wall outlet
is working. You can do this by plugging in something that
you know works and seeing if it will power on.
3: Fixing the motherboard - Run the motherboard's
diagnostic software (if supplied by manufacturer) to
ensure that the motherboard isn’t faulty.
4: Stop overheating - Change the position of the computer
to make sure that air can circulate around it. This
especially important with laptops, make sure that none of
the cooling ports are blocked.
5: Random shutdowns - Use motherboard diagnostic software
to determine if the motherboard is the source of the
problem. The diagnostic software can be obtained from the
motherboard manufacturer

13. Hard Drive Failure

 Follow the methods to make hard drive repair:

Solution 1: Reinstall Your Hard Drive’s Driver - If your
computer cannot read your external hard drive, you can
connect it to another PC to see if the drive can be read
and work normally. If it works, you can make external
hard drive repair by reinstalling the device drivers on

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 your computer. Here are detailed steps for you to
reinstall your hard drive's drivers.
 Step 1. Input Device Manager in the Windows 10
Cortana search box and click on the best match to
open the device manager.

 Step 2. Locate Disk drives and double click it.

 Step 3. Then you will see all disks on your
computer displayed here. Right-click the hard
disk with hard drive failure and then click
Uninstall device to uninstall the drive.
 Step 4. Restart the computer and connect the hard
drive. The drivers will start installing
automatically in most cases.
Solution 2: Check and Fix Hard Drive Errors with Disk
Repair Tool - You can use a professional HDD repair tool
to fix hard drive issues. There are many wonderful third-
party hard disk repair software that you can use to
diagnose and fix hard drive issues. Be sure to choose a
reliable one.
Solution 3: Repair Hard Disk Errors with CHKDSK Utility -
you can run the Windows CHKDSK utility with CMD (via
admin mode) to perform hard drive repair on Windows 10.
You can access the Windows 10 disk utility via command
prompt.
Solution 4: Format the Hard Drive - Another effective
method to eliminate hard drive errors is to format the
hard drive. As you know, a hard drive can become RAW due
to virus attack, improper operations, bad sectors or
power outage. In this case, you are unable to access the

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 hard drive data. You can format the hard drive to fix the
error.

14. Other subcomponent failure

 RAM
 Your computer may produce multiple beeps or a continuous
beep when you turn it on. These beeps can indicate many
different problems, including being a symptom of bad RAM.
Beep codes vary depending on the manufacturer of your
BIOS. You can look up the beep codes for your specific
computer to figure out its specific problem.
 If you are not comfortable fixing your computer yourself,
I recommend taking your computer to a local repair store
rather than a big retail store. Big stores are in the
business of selling additional parts, not fixing
problems.
 If you are an advanced user, there are diagnostic
programs that can help you figure out if you have a
memory problem. Your computer may have one pre-installed
by the manufacturer, or you can download a third-party
program. The Windows Memory Diagnostic by Microsoft is
also good if you suspect memory problems on a Windows PC.
 If the above programs indicate your memory sticks are
functioning, but you still suspect a RAM problem, or if
you need to find which memory module is the problem, you
can try removing the modules and placing them in
different slots.
 Motherboard
 Reset your UEFI/BIOS - It’s not uncommon for BIOS
settings, particularly overclocks and standards changes,
to cause problems with your PC. If you push things too
far, turn on a setting your hardware isn’t compatible

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 with, or disable something important, you could find your
system is unstable, won’t get past the power-on self-test
(POST) screen, or won’t turn on at all.
 Power Supply
 Make sure that everything is plugged in. It's entirely
possible that a cord could just slip out from the outlet
while you're working, so check if the power cable is
connected to the wall socket and to the power supply.[1]
If power is present to the monitor and other peripherals,
yet there is no power to your computer, there is likely
something wrong with your power supply.
 Shortly after the power is turned on, the system hardware
notices that at least one CPU is powered up and is
requesting access to a bus, suggesting that the CPU is at
least partially functioning. This assumes the function of
the master CPU and is in charge of executing instructions
from the OpenBoot firmware.

15. Component Software Failure

 Step-by-step guide to troubleshooting software.

Step 1: Free up RAM by closing other open programs - Every
piece of software uses Random Access Memory (RAM). The more
software that's running on your computer, the more RAM it
uses. This can be especially problematic if you're using older
machines that don't have a lot of RAM. So if a software
program refuses to load or is running slowly, the first thing
to do is to close all other open applications.
Step 2: Restart the software - Software problems can stem from
a conflict with other programs or simply from difficulties the
software encountered when starting up. Shutting the program
down and restarting it can sometimes resolve these issues.
Step 3: Undo any recent hardware or software changes - Changes
to software and hardware can sometimes cause software
problems, such as: Conflicts with other software, changes to

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 computer settings, conflicts with new or improperly configured
hardware.
Step 4: Uninstall the software, then reinstall it - Sometimes,
software problems occur because critical application files
have been removed, updated, or deleted. For example, many
Windows applications use Dynamic Link Library (DLL) files to
perform basic tasks. Often, several applications will use the
same DLL file. If you've recently removed one program from
your computer, it's possible you removed DLL files that
another program relied on.

16. Any System Daemons failure

 A daemon becomes the master of recovery when it notices a

failure. All other daemons are then informed of the failure.
Daemons are ordered in a strict hierarchy, and disagreements
about who should be the master are always resolved in favor of
the daemons at the bottom of the list.
 Daemons roll back their own state and any local processes
before synchronizing.
 The recovery master reads the checkpoint of the failing
daemon. Other daemons restart the failing daemon's processes
at the recovery master's command. Checkpoints from failing
processes are redistributed to make sure there are still
enough backup copies available for additional failures.

17. Data Corruption Power Failure

 Restore data from backup

If you are regular in taking a backup of your data, then you
can easily restore it and access your lost files.
Step 1: Open the control panel and look for system and
maintenance. Now click on backup and restore.

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 Step 2: Select the backup that you like to restore and
follow the wizard. After the successful installation of the
backup, you can navigate through your lost data without any
hindrance.

18. Fire
 Data loss is more likely to occur when delicate interior
computer components are exposed to numerous harmful
materials during a building fire and the subsequent
firefighting operation. After the extent of the damage has
been determined, the system ought to be put back together
properly. This can entail repairing any hardware that was
harmed by the fire, reinstalling software, and recovering
data from backups. To ensure that the system can be rebuilt
as soon and effectively as possible after a fire, it is
crucial to have a plan in place.

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