SymptomsMy Mac crashes with kernel panic quite often.
CauseThis may happen if your Mac HD has become corrupted resulting in a corrupted Parallels Desktop installation.
Resolution1. Remove Parallels Desktop application completely by following one of these articles:
For PD 7: How to remove Parallels Desktop 7 completely
For PD 6: How to remove Parallels Desktop 6 completely
2. Launch Disk Utility and repair disk permissions on your Mac HD.
3. Install Parallels Desktop application again.
Note: You will need to register your virtual machines in Parallels Desktop application in order to use them again.