Hi gauravecevnit,
1. What is the operating system installed on your computer?
2. Are there multiple updates which fail?
**Step 1:**Run Windows Update troubleshooter and check if it helps. (For Windows 7)
Open the Windows Update troubleshooter
Try to reset the Windows Update Components and see if it helps. Refer the below mentioned article for the same. (For Windows Vista)
How do I reset Windows Update components?
**Step 2:**If this does not help, try installing the updates in a clean boot state and see if it helps. To do so, follow these steps.
a. Click Start, type “msconfig.exe” (without quotes) in the Start Search box, and then press Enter to start the System Configuration Utility. If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
b. On the General tab, click Selective Startup, and then click to clear the Load startup items check box. (The Use Original Boot.ini check box is unavailable.)
c. On the Services tab, click to select the Hide all Microsoft services check box, and then click Disable all. Click OK, and then click Restart. Install the updates after the restart.
**Note:**Make sure you put the computer back to Normal Startup once updates finish installing.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
Also refer:
Troubleshoot problems with installing updates - Vista
Troubleshoot problems with installing updates - Windows 7
Hope this helps!
Syed N – Microsoft Support
Visit our Microsoft Answers Feedback Forum and let us know what you think.