PD 4.0 - VM Upgrade never finishes

I used PD 2.5 and I just upgraded to PD 4.0. The installation was done without any pain.

But the upgrade of the Virtual machine (windows xp SP2) is taking already more than 8 hours. It is stuck in Step 1 of 4 and the bar shows approx. 30% finished.

The PD application is still running and consumes constantly about 20% of the CPU performance. What should I do?

I think I did a huge mistake as I did not make a backup of the VM under PD 2.5 :-(