Read through this:
USB Device Not Recognized on Windows 7 - USB mouse
The gist of it seems to be: unplug the power cord from the laptop, remove the battery, have a cup of coffee, put it all back together, see if it works
If that doesn't do it post again.
Please don't take it in for diagnostics, or do a full system restore
until you've exhausted the help available here. It can something as simple a driver issue.