If you receive Windows Update error FFFFFFFE, it means that an update can't be installed because of a problem on your computer.
This problem is usually caused by a malware (malicious software) infection. To prevent your computer from becoming unstable, Windows won't install the update.
To solve this problem, we recommend that your reinstall Windows 7 using the Custom installation option and format the hard disk. Make sure to back up your files before you reinstall Windows 7. After the installation is complete, you can restore your files and install or reinstall an antivirus program.
Formatting erases any existing files on a hard disk. If you format a hard disk that has files on it, the files will be deleted.
Back up your files. To learn how to create a backup, see Back up your files.
Reinstall Windows 7 using the Custom installation option and format the hard disk. To learn how, see "Using the Custom installation option and formatting the hard disk" in Installing and reinstalling Windows 7.
Install an antivirus program. For more information about how to defend your computer against malware, see How can I help protect my computer from viruses?
Restore your files. To learn how to restore files, see Restore files from a backup.
Some antivirus programs are sold with annual subscriptions that can be renewed as needed, but many programs are also available for free. Microsoft offers Microsoft Security Essentials, a free antivirus program you can download from the Microsoft Security Essentials
website. You can also visit the Windows security software providers
website to find a third-party antivirus program.
Error codes this applies to: