Annoying HD blinking problem - please help!

[Aelfgeft]

I've tried all the basic troubleshooting stuff, and I'm at a loss. My hard drive light starts sporadically blinking from time to time. This is not access of any kind that I can tell. When it happens, it blinks on-off, each interval identical, lasting one second between the beginning of each blink, including the time it goes off. During the blink, the system pauses. This makes videos pause, games pause, my cursor pause, everything pauses for that fraction of a second over and over. It doesn't corrupt my downloads, or cause any real damage. Also, strangely enough, the audio does not pause. Only the video in a movie or graphical part of a game freezes. The sound remains smooth. However, It's extremely annoying while playing a game or watching a video or doing just about any continuous task.

I have one 20GB IDE Hard Drive, a Seagate Barracuda, that I have split into 3 partitions. 5GB for Windows, a 1.5GB partition for my swap file, and the rest for various light use. Don't ask why I haven't allocated the rest to the Windows installation, I just haven't had time to reinstall.

I also have a 160GB SATA Hard Drive, a Maxtor DiamondMax, all one partition. This is what I use for storage, games, my My Documents folder, etc.

Windows XP Pro wi/ SP2

I've defragged to hell and back.
I've run ScanDisk/CheckDisk on all my partitions and it found no bad sectors.
I have McAfee VirusScan 06, and the problem was happening back when I had Norton as well, so it is safe to say it isn't the antivirus.

These are my non-Windows processes normally running in the background:

Asus Probe
Internet Answering Machine
Linksys Wireless Monitor

I have one other option I have tried. I've turned off Indexing Service for folders I don't often access. Haven't noticed real improvement. Not sure if I should turn them back on or not. SO basically:

1. What is causing the blinking/pauses?
2. How can I diagnose/treat it?
3. Should I turn Indexing Services back on, or does that tend to be more of a resource hog?

Any help is greatly appreciated.

[Aelfgeft]

Somebody, please.

[Frank4d]

You probably have some process running that is hogging CPU time at a one second repetition rate. Run TaskManager. On the View tab choose Select Columns, and check the CPU Usage box. Click the Processes tab, and then click the CPU column heading once or twice until the processes are sorted from highest CPU usage to lowest.

Notice what is using the most CPU (other than System Idle Process and taskmgr.exe which do not count). Also see if the usage spikes for a process coincide with the HDD activity light.

[Aelfgeft]

Nope. Didn't notice anything out of order in the list, and the performance graph doesn't show any consistent interval activity.