Computer lags at simple tasks like browsing the web

[XeroG]

Hello! My dads computer has been acting up real bad recently (slow and freezing) and I can't seem to find the cause of it, it has quite good specs and I have scanned it malwarebytes and cleaned stuff with ccleaner.
(I can't reformat it because my dad has all his pictures and stuff on it)
[img]http://puu.sh/4cf0x.png[/img]

[djjkxbox360]

Sounds like a program in the background is using a lot of CPU or memory, check with task manager

[XeroG]

I'll do that, will report later

[naelstrof]

Freezing is the signs of a dying hard drive. You should check that out, the hard drive could just have huge seek times. In which case you should make sure it's not overly fragmented.