Windows still hanging, not sure why.

[Molsen1]

Around a month or two ago I was having problems where my computer wouldn't boot and even before that it would hang a lot when browsing files. It would also freeze when running firefox a lot as well.
At first I thought it was my hard drive and I was able to RMA that and got a replacement, but it still was hanging. I then was told that it might be my motherboard, so I was able to RMA that as well. But after that I'm still having issues with hanging when browsing files in windows explorer and firefox freezes a lot along with other programs freezing before closing as well.
I'm not sure what else to try to get my computer running normal. I have run memtest86 and it told me it found no errors with my memory.
Any thoughts on what could be causing these problems and tips on how to check for these things? Thanks in advance!

 

[ReikokuKo]

My first suspicion would have been malware. When you replaced your hard drive, did you install a fresh copy of windows? Or did you take an image of your old hard drive and load it up on the new one?

 

[MindoverMaster]

Could be your RAM eaten up. how much do you have? and what OS?

 

[carnageX]

When you ran Memtest86, did you test each stick individually, or all sticks at once?

You should do each individually so that you get accurate results.

 

[Molsen1]

I'm using Windows 7 64bit and I have 4 gb of ram. If I remember correctly I did do each stick individually but when I get the chance I will try it again.

 

[MindoverMaster]

Let each stick go a few passes.

 

[ZRMaster]

Hmmm..... Is your CPU overheating? Some SATA cables (for hard drive) have connection problems so try to take it out (from motherboard and hdd) and put it back 4 or 5 times. Try this.