It's hard to say off hand without knowing all about your hardware/software configuration. If you really think it's the hard drive access, make sure your cable is good, I've had weird things happen with faulty 80pin IDE cables. What mobo & cpu are you using?
First thing I would do is check your BIOS settings. Make sure you have the IDE set to UDMA and then in WinXP verify that you are indeed running at UDMA (if you have an 80pin IDE cable you should be running at UDMA 5 or 6 (ATA100/ATA133) on your hard drive).
Also, some BIOSes have options to "Load fail safe settings" or "Load High Performance settings", try loading the fail safe settings as the high perf. settings tend to speed up chip timings which can cause strange errors.
Of course you can also check to see if there are newer BIOS updates, that too could fix things.
On the WinXP side of things, updating drivers is of course a given, that should be done. Things to update are the chipset drivers, video drivers, sound drivers, network card drivers, USB drivers (if they are not part of the chipset drivers), video capture drivers, etc. And you should do some research on all those drivers as well because sometimes the latest versions of the drivers have known problems. For example, when I installed the latest video capture drivers for my GeForce2 Deluxe card (v1.23) the video capture feature worked fine except that half the image was blank. To make it work properly I had to track down version 1.06. Not sure why the newer versions of the driver don't work, but it's a common problem and I was able to find many posts on forums about it. Hopefully you won't need to go through any of that ####.
A good way to track down weird hardware problems is by disabling (or removing) certain hardware components. Tracking it down to a particular hardware component will make your life that much easier. Perhaps disable your sound card and see if that still causes your lockups. If not, then disable your network card. Disable all your USB, COM1/2 and parallel ports, video capture, CD-ROMs and even swap around IDE cables.
Then start disabling software. MSConfig can be a useful diagnostic tool. Shut everything off and then see if it still happens. If not, then turn things on one at a time until the problem acts up.
Also run msinfo32 (System Information) and take note of Hardware Resources->Conflict/Sharing. Make sure there are no conflicts and take note of what devices share with which other devices. Sometimes devices don't share well with particular devices. If those devices are on the PCI bus, you can usually move them around from slot to slot and they will be given different IRQs. Check your mobo manual to see which slot is associated with which IRQ or INT.
Also, in the System properties, there's a little check box to "Disable random lockups". Make sure it's checked. ;-)
- Mike