Hi all. I have an Acer Aspire 5738Z, which came with Vista Pro 32. I have since upgraded to 7 Pro 32, using the upgrade disc. The system worked fine for a little while. But then my (admittedly cheap) USB mini mouse ceased to work (turned out its wire may have had a problem) — none of the lights (the LEDs and the tracking light) showed, and 7 complained of problems with the device (I unfortunately can't remember exactly what its complaints were). That old mouse would work sometimes with some banging and unplugging and replugging. I gave up on it and replaced it with a new mouse of the same model. This new mouse's lights are lit when plugged in, but 7 does not know it's there. All my other USB devices work in every port, this mouse works in other computers, but not in any USB port of this computer. It does not appear in Device Manager, and DM will not detect that there has been a hardware change. I have used the upgrade disc to upgrade again, hoping that it will heal, and I have done everything that this forum's How to identify... thread, and I am still coming up all blanks. Can anyone suggest a solution that isn't complete system reformat (which is my next option). Cheers!