Hello everyone, just found this site, and I'm having some problems, so I'll try to explain as quickly as possible. I recently bought a refurbished Dell Optiplex GX280. I was recently getting a blue screen error "PFN_LIST_CORRUPT". Ended up reinstalling windows, and that didn't work. I then checked my ram physically, removed it, cleaned it, and now everything is fine, havn't had the error since checking the ram. But, after the windows install, some things aren't working correctly. I also reinstalled the drivers that came with the computer on a disk. I'm having problems with anything that I plug into my USB's in the front of the computer. Mouse and things like that work fine, but if I plug in a flash drive, or my printer, I get problems. When I plug in the printer for example, I'll get the "Found New Hardware" balloon, and the "Found New Hardware Wizard appears" so I click next to install. Then I get a pop-up after a few seconds that says that the hardware I'm trying to install "Has not passed Windows Logo testing to verify its compatibility with XP" and gives me the option to "Continue Anway" or "Cancel Installation" If I continue anyway, it will install, say its done and thats that. But as soon as the install wizard is closed, I'll get the pop up again telling me about the Logo stuff. If I click Cancel Installation on the Logo popup thing, the install wizard comes up and says there was an error and "the driver cannot be installed because it is either not digitally signed, or not signed in the appropriate manner." Sorry for making this long, but I'm not very computer literate anymore, and I don't know how to fix this. I'll appreciate any help given, thanks a lot.