Windows 7: Windows 7 RAM usage problem

Hello everyone,
I have a Hp Pavilion dv7 with Windows 7 Home premium 64bit. on it. I have the pc now a year and recently it crashed because of a malware program. I backed everything up and restored my pc to shipping options. After this restore I get a lot of problems with my RAM usage (my pc has 3gb ram). When I work with normal things on the computer it mostly lasts for like 1 or max. 2 hrs before it freezes and i have to reboot. When i play a game like League of Legends, it mostly lasts for like 20 minutes and 50 minutes with game booster on. The point is, before my crash , my pc didn't have these RAM problems... I played LOL as much as i wanted to but now i can't play at all.
Please help my out!
I can't stand these freezes anymore...
Thanks

Hello Rens and welcome to Seven Forums.

I think I'd try restoring the computer to factory specs one more time. It's possible that some glitch like a voltage spike, etc could have damaged or corrupted the first restore process. It's also possible that the hidden recovery partition (if that's what you used), or the recovery disks you might have used, were faulty. Unfortunately there's no way to know that until you try to use them.

If a second restore attempt doesn't fix things you're going to have to try to figure out if you're dealing with a software problem like damaged or corrupt system files causing the freezes, or if the original crash damaged the hardware. This troubleshooting guide prepared by one of our Forum experts should help.

Troubleshooting Steps for Windows 7

Well thank you! I'm surely going to use it.
A little remark, I installed Ubuntu on my pc with the Wubi installer. On Ubuntu, I can work as long as I want because it never freezes. Is it possible to conclude from that, that the problem isn't hardware but software (Windows 7) ?

I would say that since Ubuntu is working fine, there's a good chance it's NOT hardware related. So I'd concentrate on the software diagnostics . . . trying a second restore to factory specs, running a system file checker scan, trying a clean startup to see if there are any applications that might not be playing nice with Windows 7, etc.