Mouse not working after restart

[Cadence96]

I have an

Intel® Core™2
CPU 4400 @ 2.00GHz
2.00 GHz, 1.00 GB de RAM
GeForce 7600 GS
Bios Version: 5.73
and a Genius mouse & keyboard.
Windows XP Profesional
Version 2002 - Service Pack 2

Sometimes when I turn on my PC my mouse doesn't work, so I have to unplug & plug it again to make it work.
Anyone knows why it happens?
I remember the Genius set came with a software, but I didn't find it necessary to install.

Thanks

[rock08]

google then right software urself, that should help