I have a HP m8330f with XP 64 Professional and when I rebooted my computer today, out of nowhere the USB ports stopped functioning. I use a wireless mouse and first noticed the receiver wasn't powered and I couldn't move the mouse cursor. First I replaced the batteries in the mouse, although the receiver was not powered. I tried the mouse receiver in the second port on the back of my computer and same result. Tried it in both of the front ports and still no luck. I tested other USB devices on the front ports -- an old wireless mouse receiver, USB hub, etc. Nothing works. I checked in BIOS to be sure USB is enabled. It is. In device manager for the USB controllers (Standard enhanced PCI to USB host controller, Standard OpenHCD usb host controller, USB mass storage device, USB root hub, USB root hub) I unchecked "allow the computer to turn off this device to save power" in power management. No luck. I uninstalled all the USB controllers and rebooted so Windows would reinstall them. Plugged in my wireless mouse receiver and rebooted again. The receiver powers and stays on until Windows boots. I'm out of ideas and not sure what is going on. It seems to be an issue with Windows and not the hardware, but why would it happen out of the blue like this? My last resort will be to install Windows, but I hope it doesn't come to that. I'm hoping someone will have more suggestions to try! Thanks for the help. Edit: Oops, sorry, I overlooked the "General Hardware" forum so this might belong there.