There have been reports that UFT runs well with Windows ME, but I have not upgraded my Windows as yet. It may depend upon which version of the program you are using, too. In the case of the gal who is using a Mac, Version 1, I believe, was the only one that ran with Mac and it was never upgraded ... simply discontinued. Her only option is to use the REUNION program.
So ... which version are you using of UFT? Can you tell us what what type of errors and WHEN you are getting those errors? How are you trying to install the program? Did you install from the original CD? From a backup? If so, did you back up libraries and all?