Mouse freezes, computer locks up.

My computer is less than a year old and has recently come back from the shop. Some virus had gotten into it (I don't know the details, just that it took them three days to fix it) and while it was there the repair people installed two anti-virus programs: Malwarebytes (Free) and Avast (Free).

Previously I had used Microsoft Security Essentials.

Ever since getting it back 5 days ago I've been having problems. The mouse will freeze and the computer locks up. I have to do a hard reset to get out of it. After this freeze, the computer runs fine. Until the next morning. (I turn my computer off at night; I don't leave it running.)

Yesterday I uninstalled Avast and re downloaded and installed Microsoft Security Essentials. Everything seemed fine, but this morning, after having been on for half an hour or so, the same problem: The mouse froze and the computer locked up.

During the week I used my lame google-fu and saw that many people had similar problems to mine - and many of them had Avast - which led me to think Avast was the problem, which is why I went back to MSE. But I'm also seeing threads where people have similar complaints with Malwarebytes.

Does anyone have any advice for what I could do to fix this?

 

Hi. I would run a full scan with Malwarebytes in Safe Mode. Tapping F8 on boot normally.
Post if it finds anything.
I am not sure the Computer Shop got rid of your viruses completely.

 

In addition to DSTM's advice above. It is very unlikely that either Malwarebytes or Avast have caused your problems. Just like DSTM, I believe that you still have an infection on your machine.

Running Mbam in Safe Mode should ensure that whatever malware is running on your computer is not given the chance to start up. Some malware programs have the ability to stop our anti-malware programs from starting up, plus blocking an internet connection to download an antivirus or anti-malware program. And by running your computer in Safe Mode the malware is not able to start up its self.

Note: From the startup options screen, you should choose Safe Mode With Networking. Choosing this option will enable you to update MalwareBytes before running a scan.