To reinstall Parallels Tools with Parallels Desktop:

1. Click Actions button at the top Mac menu. If your Windows is running in Full-screen mode and there's no Mac menu, put the cursor at the very screen top and leave it there for a while, or press Option+Ctrl.

2. Select Reinstall Parallels Tools. If nothing happens open Windows Explorer and double-click Parallels Tools virtual DVD-drive to start reinstalling.

To reinstall Parallels Tools from inside of Windows:

1. Launch Windows virtual machine.

2. Disable antivirus software in Windows.

3. Click Start > Settings > Apps > Apps and Features (or right-click on Start button > Control Panel > Programs and Features) and remove Parallels Tools if present.

   

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4. Proceed with reinstallation.

5. Restart Windows.

6. In Mac menu bar, click on Actions (Virtual Machine in older versions) > Install Parallels Tools.

7. Restart Windows again.

8. Enable your antivirus.