Win 7 and workstation setup error

I received a screen shot of an error message: "Setup cannot extract the disk drive letter from the Mas90 directory path \\server-name\shared-folder\Mas90. Please make sure you are running Workstation Setup from a mapped network drive or a local drive, and not a UNC path, and run workstation setup again.

 

Any ideas on why the drive letter mapping isn't being recognized?

 

I verified that the user is in fact running from a mapped drive letter but here's the catch " Workstation OS Win 7 but the MAS version is less than 3.71, perhaps even 3.41". The user claims he had it working before but had to rebuild the machine due to a virus. Obviously this Mas version is no longer supported, never mind on Win 7. I've told them to make sure they have their IT people check user admin rights locally on the PC and on the network.