Troubleshooting Steps in case of partially Installed Issues for Bitdefender GravityZone Agent

1. reboot system in safe mode
2. Run CMD as a Administration
3. cd <path of BEST Uninstall tool>
4. BEST_uninstallTool.exe /bruteForce /destructive
or 
4. BEST_uninstallTool.exe /bdparams /password=your_plain_text_password

Afterwards you will need to remove the following Registry entries and folders present on the machine:

• HKEY_LOCAL_MACHINE\SOFTWARE\Endpoint Security.remove
• HKEY_LOCAL_MACHINE\SOFTWARE\Bitdefender
• C:\Program Files\Bitdefender; (if present)
• C:\Program Files (x86)\Bitdefender; (if present)
• C:\ProgramData\Bitdefender; (if present)

also check for the if bitdefender drivers are not there under C:\Windows\System32\drivers if present then remove it manually .