Windows Update was a functionality brought out originally to keep your Microsoft software up to date. It includes “Patch Tuesday” security updates, and no one is disputing that all this is useful, and some of it is even necessary. However, at the end of it all, a lion’s share of users find their computer running slow. If you have done an update recently and are now left wondering “Why is my computer so slow?”, there are some things you can try to remedy the situation.

• Restart the computer. This is one way to make many problems disappear, including some following Windows Update. Older versions of the OS like XP had the problem that a single reboot was enough for the changes to take effect.
• Are you unable to access some websites in Internet Explorer? Try resetting the Security Zones of the program to the default levels. This might solve the problem.
• Are you getting trouble from a hardware device? Is it bringing up an error message when you try getting it to work? If so, update the device drivers.
• Is your antivirus failing to update? This issue, if you face it, is a serious one, because it leaves your PC vulnerable to new malware threats. The solution is to update the definition files of the antivirus program, so that the latest threats will not slip past its defenses.
• If the default programs for file extensions have somehow changed, reset them to the way, you had it before the update.

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  Do a System Restore. This will remove the Windows Update(s). This is a good idea since it reverses all changes made by the updates.

• Go to the Run command and try running sfc /scannow. This is to see if any Windows files have gotten deleted or corrupted. While System File Checker (sfc) is not a foolproof solution after Windows Update, it is still the next best thing if a System Restore does not help you.
• Test the RAM and the hard drive. Updates cannot have physically damaged either, but a patch being installed may have started off something problematic.

These are some of the generic steps, which you can take to get your computer’s speed back to normal after Windows Update has slowed it down. If they do not work, you will need to choose a method of repair based on your specific OS version.