How to fix error 0x00000057 when installing a printer driver, no permission to write to DriverStore?

We have a customer with a PC where installing a particular local printer fails with error 87, "invalid parameter". Usually I'd blame the installation routine, but when looking at Process Monitor it seems like writing to c:\windows\system32\DriverStore fails.

The printer to be installed in this case is the Amyuni PDF Converter. The error looks like this (message says "Arguments invalid.").

Then trying to install the same printer using the Windows "Add printer" function (message says "Could not install print driver. Process could not complete (error 0x57)."):

This is what Process Monitor reveals and is most likely the cause of the issue:

The question though is how to fix it. The permissions on "DriverStore" are Everyone Read,Execute and SYSTEM Full access. This would certainly explain why the Install.exe, running as local admin, cannot access this folder, but this permission setup seems to be the default when comparing with other Windows 7 systems where the same procedure works just fine. I tried changing the permissions of this folder for more generous access, but these changes seem to get reverted automatically so that doesn't help.

Any idea how to fix the problem?