OK, I've finally got Poser 7 uninstalled and then reinstalled to c:/Poser7.  Along the way I managed to lose my P7 Runtime with a lot of purchased material (stupid mistake) but thank God I had backed it up to an external HD and was able to recover it all.

I will let you know if I continue to have any problems.

My thanks to all of you who have offered advice.

Merry Christmas to you all!

Scarab