First of all, I'm going to give you my system specs:
CPU: Intel I5 750
GPU: GeForce 550Ti 1GB
MOBO: Gigabyte H55M-UD2H
RAM: 2 x 2GB DDR3 1333 (Corsair)
Power Supply: Topower 800W
SO: Windows 7 x64
Every single driver is update and I have no issues whatsoever while using my PC normally.
THIS is my problem. I recently bought a new RAM (DDR3 4GB 1333) but a different brand: PCBox. I think it is really generic; but given that my country, Argentina, has new importation restrictions, I could not find a better brand. Whenever I try to run my PC with that RAM, it just gets into an infinite reboot loop. It doesn't display any image either. When I take off this RAM, it works just fine. The seller give me a new one when I told him about this problem, but it keeps happening even with the one (of the same brand, of course). Could it be that I'm using THREE RAM modules? Or maybe the brand is so generic that my PC refuses to use it? I don't know, I'm completly lost.
3 RAM modules are actually hindering you ...Ditch the third stick of RAM and either use 2 or 4 modules.....Like mbarnes86 said go for a 2x2GB instead of the one 4GB module that way you maintain the system in dual channel mode....Import sanctions are completely stupid...I wish I could ship you some nice sticks of RAM instead of that crap you are stuck buying....