Hello all. I have recently built myself a new system from scratch, and it was working amazing for a long time. Now, however, I have been getting lockup issues. My computer will stop responding all together for a few seconds to a few minutes. I have control over my mouse, but all open programs lock up. This happens MOST when i open a web browser. I use Mozilla Firefox, but i have tried Chrome, and Internet Explorer 8, and they all do the same thing. The browser stops responding, i hit Ctrl+Alt+Del, and sometimes it takes a few moments for the menu to open. I then proceed to hit "Task Manager" and that sometimes pops up right away, or other times it takes several minutes to come up. I end the process and everything works fine. It has started pausing occasionally in games as well (Most prominently Call of Duty Modern Warfare 2). It is infrequent for that to occur though. At first i thought it might be my memory, which was overclocked at 1066hz (as it is meant to be. it has its own heatsync and is advertised as 1066 RAM. So i reclocked it to 800hz. This did not solve the problem however. I have run a basic Memory test that comes with windows, and it has no errors. I have also downloaded a hard drive tester from Western Digital since i own a WD hard disk. That also came up with now errors in either the basic or advanced scans. I cannot seem to figure out what my problem is. I even so much as reformatted my hard drive. I will supply my setup as follows: Q9400 Intel Quadcore CPU @ 2.66GHz Nvidia GeForce 9800 Gtx GPU 4GB's OCZ ram @ 800hz (previously 1066) 750watt PSU 1TB Western Digital Hard Drive (SATA) Windows 7 32-bit CPU idle temp: 36*Celsius GPU idle temp: 60*Celsius (the 9800 has a max temp of 105*, so its cool) Does this sound like it might be a Memory error, Hard Drive error, or Power Supply problem to you? I have not been able to figure it out. HELP! lol thanks all.