Explorer/PDM workgroup error 1722

I have to do a manual install otherwise dwgeditor &eDrawings throw up registry key access problems.

When I get to the explorer or the pdm workgroup install both failat the point where the box says removing backup files. Afterclicking ok the install rolls back.
This is a clean install and I've run a registry cleaner on thesystem. But it still fails to install with error 1722 failed toregister pdmworks.dll.
It is possible to register the dll manually but as the installrolls back this is no use.
the pdm service actually starts, it can be seen in the task managerbut, obviously, stops after the rollback.

ALL the av options have been turned off.

Any ideas?


I'm aware the graphics card is not supported but everything elseworks fine (at the moment).
SolidworksAdministration