I have faced this issue when My computers just restart when ever I connect a specific memory card, USB drive or any other portable device. This is quite a serious problem which is on the other hand simple to fix if this is happening due to corrupted data on your USB Storage Device. please give my solution, If no way to handle this problem, I wanna reinstall my windows xp.
I have a simple solution, try this; In order to fix a removable drive if the data on the drive, you can run scandisk in windows by right clicking the drive icon in my computer, go to right click on pen drive and select properties, now click the tab tools and run a check disk on your pen drive. you just need to click on check now to start disk checking and repair any errors caused due to corrupted data on your pen drive. try this, maybe this can help your problem
Its really hard to tell with the information thats there to work out what exactly is the issue. There's two avenues that you can follow if this is an OS related issue.
Follow the blue screens - Turning off rebooting on failure is what's usually suggested, but you can get a good idea of what caused a bluescreen of death with nirsoft's bluescreenview - which lets you look at bluescreen information, or resplendence software's whocrashed. If its a windows issue, this should tell you what's the driver causing it. Uninstall, and replace off windows driver service or a known good copy
The other thing i'd consider, though unlikely is a hardware fault. If the computer reboots from specific sorts of usb ports, independant of os (so, give linux a shot if the blue screens yield nothing), then there may be a short or other issue somewhere.
I've seen windows systems freezing due to a failing hard drive on an ipod as well, but without more information on what's failing, its hard to tell.