Opening Folders Causing A "class Not Registered" Error

I'm not quite sure why this error is appearing, it worked fine earlier today but since restarting my computer when I try and open a folder on the launcher I get an error saying:


C:\

Class not registered

I don't know why this would start to happen after a restart.

If someone could tell me what causes this error, whether it's related to the program or the OS or a dependant application.

The only thing I remember changing is installing .Net Framework 4.0 so I don't know if that would be causing the problem.

Thanks in advance to anyone who replies :)

#541872