Windows 7 Freezing in Intervals

Hey everyone. My system consists of the parts below:

Core 2 Quad Q6600 @ 2.4
8GB OCZ DDR2800 RAM
SLI 9800GTX+
Western Digital 640GB HDD

I recently installed Windows 7 Pro. However, I've been encountering a problem that I didn't have with XP. After I boot my system, every 4 seconds, the system freezes for a moment, then resumes. As you can probably guess, this is aggravating.

At first it didn't start until I started using Firefox. I noticed it was using more memory than usual, and after I closed FF, the system went back to normal. However, it started again after I started transferring music from one partition on my hard drive to the other, and now it doesn't stop no matter what.

I noticed that before the system froze momentarily, the CPU usage would drop to 0%, then start up again when the system resumed. I've tried updating my motherboard drivers, along with Windows Updates, but nothing seems to work. My laptop which is running build 7100 works flawlessly, and I'm fairly clueless at this point.

I've reinstalled Windows 7 twice already, and it's happened both times. Any idea of what could be causing this?

Does it happen in safe mode (press F8 at startup to get there)?

No, it doesn't happen in Safe Mode, which leads me to believe it's some background service or process. However, the only programs which start with my computer are Steam and HDD Health. I have a feeling it's some obscure background service.

Giggers said:

No, it doesn't happen in Safe Mode, which leads me to believe it's some background service or process. However, the only programs which start with my computer are Steam and HDD Health. I have a feeling it's some obscure background service.

Try using the MSCONFIG utility to boot in "diagnostic" mode. It that works (no symptom), use the "selective" startup mode to switch things on and off until you zero-in on the culprit, after a whole bunch of reboots.

Giggers said:

Good news. Diagnostic mode has removed the problem. Now I need to go through the long process of finding which service it is. Does anyone know the best way to do this in 7?

EDIT: Okay, interesting. Everything is fine until I tried to copy pictures out of my Windows.old folder from my last install to my new pictures folder. It seems accessing the Windows.old folder, or maybe trying to work with files on it, causes the system to start freezing. What? Is this an early sign of hard drive failure?

Not if it doesn't happen in "diagnostic" mode.

On the other hand, if you're saying that accessing the "windows.old" folder somehow seems to kick off the periodic freezing irrespective of whether it's done in safe or normal modes, that may potentially point to the hardware (not conclusive yet).

Try doing a full CHKDSK /R on that disk partition.