I'm running a Dell Dimension XPS 410 desktop with Windows Vista. A week ago, I came back to my computer that was on sleep mode and it wouldn't come back on when I moved the mouse. I cold booted and got an error message that a USB device stopped working but everything worked. This happened again today and when I cold booted, II noticed that I had no mouse cursor so I thought it was the USB mouse. I cold booted and everygthing works fine. I went to device manager and there were no yellow exclamation marks nor were there any such marks anywhere in device manager.
I'm not sure if a device had actually failed as a piece of hardware doesn't "heal" once you reboot so I'm not sure if it's an external device or a windows issue.