I have the same problem as seemingly many other people here, and I think we might all be experiencing the same issue: a compatibility issue in Windows 7 between hard drive and network controller or drivers.

I've tried firmware updates of my entire board, wiping my drive and reinstalling from scratch. And yet the problem persists, which suggests it is an operating system error, as the hard drive checks out 100% physically.

Additionally, the only time it does not occur is when in safe mode WITHOUT networking.

With networking, there are spikes in disc access every so often and a huge flow of processes accessing the disc simultaneously that literally "stick" the disc, and physically jolting my computer unsticks it.

Again, this has been tested for hours in a professional service environment, and without network access on, things are fine. As soon as there's network access available, the disc access occasionally cranks up to 100% and sticks everything.

I'm using Microsoft Security Essentials, but this also happened under Norton, then McAfee.

Again, this happened again after a complete wipe, so the likelihood of malware causing it seems low. I don't visit unsecure sites anyway, as far as I know.

This, to me, narrows it down to a Windows 7 process that is somehow repeatedly corrupted, perhaps a corrupt .dll or driver, causing a conflict at the operating system level and temporary hard drive failure.

I would encourage anyone who knows more about this stuff (which is probably most people!) to take a shot at this one, and I would encourage anyone else with a sticking hard drive in windows 7 64-bit to check on whether it occurs during safe mode without networking.