Hi. New here, and I've got a problem all the same.
 
Two years ago, I got a 40 GB Maxtor 3000LS external HDD. Worked like a charm. I stored all my music and picture files on there without a hitch. Fast forward to this past month, I move the computer home with me on a college break and the external is working fine. Give it another few hours, and suddenly I can't access it anymore. I had updated Windows XP (Pro) during that period, so I did a System Restore to see if that fixed the problem. It didn't. I called a friend for help, and his ultimate suggestion was to reformat (he relayed the problem to, basically, some sort of fault in the main hard drive, through spyware or a virus or whatever, that kept the HDD from being accessed anymore).
 
Now, whenever I attach my hdd, it appears in device manager and My Computer perfectly fine. Oddly the manager says that it is empty, but when I hooked it into another computer (running ME), I could access all my files okay. Whenever the hdd is attached to my computer running XP, I can no longer access Add/Remove Programs, and it keeps prompting me to Format the hdd. It is FAT32, but only because it came that way and I had no prior knowledge of this stuff until the problem arose.
 
I reformatted and got Windows back up to speed, and the hard drive will still not work. Same problem as before. I really don't want to lose the files on there, but I can't find a way to give myself access again without doing so (and finding an older computer with Windows 98/ME/2000 to temporarily hold my files). Anybody run into this issue before, or have any suggestions? Much appreciated.
 
EDIT: The same problems show up on other systems running Windows XP too. And changing the USB port doesn't make a difference.