Download error: Failed to convert sldIMDownloader 2.0 to a CLSID

The version is 2012 x64, SP4 on Win7 64-bit.

This is the error returned when I try to run a download. It gets past the serial number & system check, all the way to newer version available, then generates the error. If I try the "manual download" it returns an error "The downloader could not be started due to an internal error. Try downloading manually." As near as I can tell from looking at the logs, it hits a point where it cannot create registry entries; but no indication as to why. The permissions seem fine. The user is a local admin. (The results are the same when logged in as Administrator, so I doubt if it is a permissions issue.)

The network guys assure me that nothing is being blocked by the firewall or GPO. I don't actually use the software; I'm just the Desktop tech trying to make it work.

Thanks for your help!

SolidworksAdministration