Desktop keeps freezing/lock ups

[Damianfishy]

Hi all, I've been having a problem with my desktop it's been locking and freezing up alot recently will do it when basic web browsing or gaming. It's pretty slow on boot up also.

The computer is an Acer Aspire AM3920
which has a
Intel core i5 processor 2300
8GB DDR3 Vegenace ram
600W PSU
1TB Hard drive
Nvidia GT430 graphics card
Running on windows 7

This problem occured after recieving my PC back from a repair from Acer around 5 months ago (they replaced the HDD) I've been using it for 5 months since and it started freezing when I received it back but now the freezing is allot worse.

I have tried basic things like a memory test to check if bad RAM but it passed all the tests, I have tried using malyware bytes but no luck.

If someone could give me some help it would be appreciated

Thanks

 

[Tmagic650]

Check the hard drive by going to Computer, and right-click on the C drive. Select properties, tools, check now. Put a check mark in both boxes to set a disk check on the next start up. Also, download and run this temp file cleaner:
http://www.geekstogo.com/forum/files/file/187-tfc-temp-file-cleaner-by-oldtimer/
These tests will give us further clues

 

[Tmagic650]

In the bios, turn off CPU thermal and power saving settings. Also, disable C3 and C6 states. See if doing this stabilizes the computer