Thank you for responding.  There must be something still in my registry (?) that is causing the problem/conflict.  I decided to try it on my laptop.  It is installing there with no problems.

Any suggestions?  I originally started with version 7 years ago and then upgraded to 8 and then to 11 Plus/Ultimate.  My computer crashed and I'm trying to reinstall 11.  I no longer have my version 7 CD, but have the upgrade CD for 8.  It seems to take that okay as the prior version to install the upgrade CD for Version ...