Parallels Tools fails to install at 55% with the error:
Failed to install driverprl_tg.
C:\Windows\inf\Setupapi.dev.log (please check before applying the solution):
[G] !!! sto: Driver package signer is unknown. Assuming untrusted signer. Error = 0x800F0242 [G] !!! ndv: Driver package failed signature validation. Error = 0xE0000242
Shut down virtual machine.
In Parallels Desktop top bar: Actions > Take a snapshot.
Mount Windows disk with Parallels Mounter:
- Right-click on Virtual Machine in Parallels Desktop Control Center > Show in Finder
- Right-click on Virtual Machine's 'pvm' file > Open with > Parallels Mounter
- Windows volumes will appear in Finder, at the 'Favorites' list.
Copy the attached certificate.cer in the "C:\" location.
Unmount Windows disk (right-click on mounted disk in Finder and choose 'Eject').
Start virtual machine.
Go to Start, in the search box type mmc and hit Enter (return).
In the Console menu go to File > Add/Remove Snap-in... > choose Certificates > click Add > button > in the appeared window choose Computer account and click Next > Finish > OK.
Go to Certificates - Current user > Trusted Root Certification Authorities > Certificates > locate and remove all entries of Parallels*.
Go to Trusted Root Certification Authorities > right-click Certificates > All Tasks > Import... > specify the path to the copied certificate (that is located in the disk C:) and proceed with the Certificate installation.
Go to Certificates - Current user > Trusted Publishers > Certificates > locate and remove all entries of Parallels, Inc.
Go to Trusted Publishers > right-click Certificates (IF THERE IS NO Certificates > Right-click Trusted Publishers) > All Tasks > Import... > specify the path to the copied certificate (that is located in the disk C:) and proceed with the Certificate installation.
- Try to install Parallels Tools and check the issue.
NOTE: In case it still fails, do the following:
- Run Command Prompt as Administrator.
Execute the command:
sc delete prl_tg
- Reboot Windows and check the issue.