Failed Windows 7 update, getting error 800F0900

Hi,

1)      Is the issue specific to an update?

2)      What is the exact/complete error message?

Method 1: I would suggest you to run the Windows Update troubleshooter.

http://windows.microsoft.com/en-US/windows7/Open-the-Windows-Update-troubleshooter

You may also check for the failed update:

If you go to windows update, click on review updates, and it will show you what has installed or failed.

Download the Windows updates when the computer is set to clean boot state and install the updates

Method 2: Clean boot

How to configure Windows 7 to start in a "clean boot" state

http://support.microsoft.com/kb/929135

Note: After troubleshooting, make sure to put the computer to start as usual as mentioned in Step 7 in the above KB article.

Method 3:

Some users fixed this issue by resetting windows updates components. Try the following steps and check the result.

Method 1: Reset Windows updates components.

Login as an administrator.

a.       Visit http://support.microsoft.com/kb/971058

b. Click Microsoft Fix it and run it successfully.

c. Restart the computer once the tool is run.

Note: This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs.

Let us know if this helps.