MS wireless optical mouse

A month ago I bought the MS wireless optical desktop pro which came with wireless keyboard and mouse. It has been running fine for a month under windows xp pro sp1. But what happen is after I run the defragment tool for the first time, the wireless mouse is not working, cant move the pointer and cant click. However, the keyboard is working fine. And xp shows that the device is working properly. And I also tried everything that the troubleshoot menu suggest, but it still not working. I wonder how can I fix this problem? -_-