Windows 8.1, 'locks up' every few hours, ctrl+alt+delete fixes it

I am running:
Build 9.0.23350
(Revision 941886; Monday, November 11, 2013)

Windows 8.1 on Mac OS X Mavericks.

For the last month or two, Windows 'locks up' every few hours. I can still move the mouse, but I can't click anything or rollover.

Pressing Ctrl+Alt+Delete works, bringing up Task Manager then makes the mouse work again.

How can I fix this?

(Update: further information, if the cursor is in a text box - Visual Studio say, I can still type in it - it is just the mouse pointer that moves around, but is unable to interact with anything. This happens in coherence mode AND full screen).

 

Hi niico100,

Update Parallels Desktop for Mac to the latest build by following the link: http://kb.parallels.com/111603

Thanks,
Looran

 

I have done this, after around 5 hours of operation today I had the exact same issue again.