Hello,
I have seen this issue a few times and the resolutions have varied depending on the system. First make sure that the system is clean. If you can get a copy of the uninstaller through your QC/ ALM administrator, then run it on the system to insure that everything is uninstalled on the client system in questions. Second make sure the user has administration permissions when initially trying to install, as this sometimes can resolve the issue. If this doesn't work insure that the client has read/write permissions to the location where the file is being written to. If the file exists then you can try to manually register trhough the following ways 1) right click the file and select the properties option and then within that mention select the option to register or 2) through the command line executing the regsrvr command. If none of these work, I have been able to successfully copy the files from another current system that is working correctly.

I hope these suggestions help,
Dan