Upgrade won't run

[tortured]

7.5.508 with updates 7.5.14.102 on Server 2003.

 

When I run Check Updates it offers 7.6.111. When I click More Information About This Update I get an empty page. When I download and run the update it terminates at the "Removing Applications" section with message as follows:

 

"The path c:\windows\temp\RetroInst\Retrospect 7.5.msi cannot be found. Verify that you have access to this location and try again, or try to find the installation package 'Retrospect 7.5.msi in a folder from which you can install the product Retrospect 7.5."

 

This makes little sense because the product I'm trying to install is not 7.5.

 

If I run instead of download and run, the message is slightly different:

The file "C:\...Desktop\RetroInst\Retrospect 7.5.msi is not a valid installation package for the product Retrospect 7.5. Try to find the installation package "Retrospect 7.5.msi in a folder from which you can install Retrospect 7.5"

 

It all terminates on error 1714, The Older Version of Retrospect 7.6 Cannot Be Removed, which also makes little sense, as I don't yet have 7.6.

 

I have tried putting the requestd 7.5 msi in various folders including the unpacked installer folder. No luck.