Error installing Toad. "1622 - Error opening installation log file." (94537)

During the installation of Toad, after the product selection page and installation has started, the installer gives the error:

"The installation of component Toad for Oracle has failed with the following error:

1622 - Error opening installation log file. Verify that the specified log file location exist and that you can write to it.

For further information please view the log file located at:
C:\ProgramData\Quest Software\Quest Installer\Logs\Toad for Oracle 11.5.msi.log"

Conflict in the installation directory.

Verify that you have admin privileges for installation.

Veirfy that you have access to the C:\ProgramData\Quest Software\Quest Installer directory.

Veirfy that you have access to the intended installation directory
- in 64bit OS C:\Quest Software\Toad for Oracle
- in 32bit OS C:\Program Files\Quest Software\Toad for Oracle

Try installing one product at a time.