Dave,
you can uninstall Parallels Desktop from Boot Camp. To do so please open 'Add/Remove programs' control panel in Windows and remove Parallels Tools if present.
If you want to uninstall Parallels desktop please do the following:
1. Open your Boot Camp virtual machine.
2. Open Configuration Editor
3. In the Resource list, click Hard Disk.
4. In the hard disk settings pane, click the 'Advanced' tab.
5. In the Cleanup Boot Camp Partition area, click the Clear button.
6. Then choose VM menu > Delete VM from Parallels Desktop menu bar and follow the on-screen instructions. It is recommended to leave the default values intact. (Please note that this operation is irreversible. The Virtual Machine will be deleted, and there will be no way to restore it.)
7. Uninstall Parallels using the Uninstall Parallels Desktop application from the original package you used to install the Parallels Desktop.
But if you will provide me with blue screens you got in Parallels we will try to solve your problem and there will be no need to uninstall Parallels Desktop.
Best regards,
Stacey