strange mouse problem

I have a user with Parallels 8 and today informed me of a strange problem.
On the parallels side the mouse goes with with a lillte box and an arrow.
Uses is unable to click on any desktop item but can access throught the
start menu. I've checked mouse settings, shutdown,, restarted....still the same.
any ideas greatly appreciated.

thanks

brent

 

Reinstall Parallels tools.

 

I got this notice as I wa returning to reply - that was exactly what I did...worked like a charm - ty.