The last Windows update made my computer five times slower than it was

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This week I was prompted that Windows would end their support for my version of windows and that I had to install 20H2. I found it odd that some people already had that update since way before, but I didn't pay much mind. I did so, and it took forever, after it was done, my computer became quite slow. I saw I still had a couple of updates remaining, so I thought that might help. It did not. I shouldn't have installed this update. I have a Legion Lenovo gaming laptop, y520, which should support heavy games, and barely more than a year old, but now it's slower than my 10 year old Win7 pc. I don't even play games most of the time, if anything DCUO or Gmod, both pretty old games. But my computer now is super slow, and it struggles running something as simple as chrome or Opera. And not even fast tabs. What do I do to go back to my normal speed? Please help this is unbearable. It's almost as if I had a 2gb ram.

7 Replies

Hello @Charles1810,


Suggest you to run System File Checker scan:


1. Search for 'command prompt' using Cortana or Windows Search.


2. From results, right click on Command Prompt and select Run as administrator.


3. Type sfc /scannow command and press Enter key.


4. Let the command complete and then reboot the machine.


If issue still persists, perform clean boot:


Let us know if this helps!

Come on... "sfc /scannow"???

Everytime I tried using that "tool", it always ends up either crashing or finding no problem.

As to the "Clean Boot"... Really, you really think running your PC is safe mode is an acceptable answer to Microsoft breaking a previous clean installation that was fine?

The real answer is to provide the poster with the ability to undo this supposed upgrade.
It is basic troubleshooting steps for general Windows issues and while you might not see the sfc fixing any issue, in other cases, it actually solved problems. Running Clean Boot is different from the Safe Mode. In this case Windows will boot normally while with minimum services and we also advise them to try Safe Mode to diagnose the issue, so in case issue didn't reproduce in the Safe Mode or Clean Boot, then we could ask user to enable services one by one or check installation status to identify what causing this failure.
In addition, sending report through the Feedback Hub app is also recommended , so Windows team would be able to investigate this issue.

SFC /SCANNOW is the first troubleshooting step for most of issues in Windows. It is to identify and fix, if there is something wrong with system files. As Reza said, it is the basic troubleshooting gives good results in minimum efforts.

Clean boot is clearly not Safe Mode.

Clean boot:

Safe Mode:

Reverting the upgrade is last option IMO, if basic troubleshooting options failed.

(Op) No I completely agree with peter. It seems that with every update I allow windows to perform into MY computer, it gets **bleep**tier and **bleep**tier for no reason. I performed both the scan and the clean boot. Big surprise. It doesn't takes a computer genius to realize at this point. That windows update effed up both my wifi and video drivers. This is ridiculous, I bought this laptop a year ago, it's got really great specs, and yet, now it takes forever to load a website, even with a 5g 200mbps connection. It takes forever just to load, let alone show chrome or opera. I've been taking good care of this computer, one update and it feels like I installed malware. I'M GOING TO CALL MY LAWYER. Coss I now I need to buy a large usb stick that I don't use, for no other reason that I need to backup my pictures, videos and music, BECAUSE WINDOWS UPDATE MESSED UP MY DRIVERS. and I need to see if a factory does the trick, since I heard windows forces it's updates even in a factory version. Because, hear this, updating your drivers in device manager does nothing as well.
I'm gonna call my lawyer before all this, because this is glorious. My computer is sparkling clean. I haven't done other than download files from email, with a premium antivirus. And now it's working worse than windows xp
Honestly, without inspecting the log files and events it is not easy to say what causing this issue , update may or may not caused this issue. However, because this is public forum, it is not a good idea to share log files.
Are you able to boot into your PC?
Take a look at: