why does my computer freeze?

[Misunderstooduncle569]

I am using windows 8 on my computer and I had Kaspersky scanning for viruses I also have Malwarebytes and AVG I read somewhere that if you have more than 1 Virus scanner it can freeze your computer even offline. Malware Bytes wiped out a lot of files on my Laptop that were infectious and blocks any malicious sites as I receive notification of it all. But out of the blue my Google Chrome freezes then everything begins working again. Every now and again the whole thing will just freeze entirely and the cursor can't move my media player freezes as well and the sound of the movie I'm watching remains but the picture goes away. Then when it unfreezes the whole Player escapes then the screen freezes again. What should I do? Should I just use 1 virus scanner? do I have to uninstall and then reinstall google chrome again? I need my computer all my stuff is on it I can't lose any of these things there are very important documents in my computer. Please someone help.
Secondly sometimes when I run my anti virus stuff the computer freezes halfway through the scan.