I appreciate the work you did to support this problem. I contacted the customer again, and they said it now works. I am not sure what he did, but I told him to turn off all programs and virus protection, and it worked.
I do have a follow up question - if the customer does not have a c:\ drive (perhaps they change it to f:\ for some odd reason - some customers do this), the installer fails. There must be something hard coded in the installer. I tell customers to map their f:\ drive (for example) to the c:\ drive, and that takes care of the problem (a bit clunky, but it works).
Any ideas?