frustrating mouse

[Andy]

I have recently upgraded 98SE to XP with success, however,
when I boot up my mouse will not work at all.

This appears to be a random fault as when I restart the pc
the mouse works fine

Day after day this happens - first boot no mouse second
boot is ok but not always in that order - how frustrating
is that

I have downloaded the latest drivers from microsoft and
re-installed but no change

The mouse is a standard microsoft intelli mouse with a
wheel and worked perfectly with 98SE

Can anyone help