SymptomsSome windows of the virtual machine are distorted (pixelated).
CauseThere might be a problem with Video Adapter installation or driver conflict.
1. Update your Parallels Desktop to the latest build. Please refer to the KB 111603 for more information.
2. If you are using Parallels Desktop 6 install the latest build that is available from KB 5802.
Follow the Step 2 if the issue persist.
1. Insert the Bootflag in Virtual Machine menu -> Configure -> Hardware -> Boot Order, refer to KB 111767 for more information.
If the issue persist follow the Step 3.
1. Uninstalled and reinstalled Parallels Tools from Control Panel. Refer to KB 8969 for more information.
If the issue persist follow the Step 4.
1. Uninstall Parallel Desktop completely by using the steps mentioned in the KB 112189.
2. Reinstall Parallels Desktop application.
NOTE: In case none of the solution above helped please contact Parallels Technical Support.