How do I delete search paths?

Due to changes in our network I'm trying to delete some defunct search paths (System Options - File locations - Search paths). When I save and close the settings window, the changes are gone and the old paths are stille there.

This is not related to user privileges, as it seems that these paths are not written to the registry. Other setting stick OK. I've found an article on the web that mentions editing these paths using SolidWorks Explorer, but that is not accessible any more.

Anybody had any luck changing these settings - or should I just leave them as is?