Error due to insufficient access to registry key HKEY_LOCAL_MACHINE

If the installation on the terminal server fails due to an error writing to the registry: HKEY_LOCAL_MACHINE32\Software\Classes\.pdf, the problem can be solved by locating this registry folder and checking the access rights.

The typical issue is that no security is set on this .pdf area of the registry (not even local Admin had access). After giving rights to domain admin the install will complete successfully.