Microstudio 4.006 problem: inaccessible

[EclecticProf]

In July, I loaded Microstudio 4.006, Keywrite 2.012, KHPro 4.107 and Vogone 2.001 on my new Dell XPS running XP. After the initial shake-down, all was well. I used Microstudio and Keywrite successfully. I then upgraded to Keywrite 2.10 on 9/16 and problems appeared. Sometimes, when I clicked on Microstudio, the hourglass would stay on for 5-10 seconds and then disappear. The program never presented a window on the screen and did not appear in the task bar at the bottom. Yet, using the task manager, I can see Microstudio.exe occupying about 7,696K with CPU=00. My overall CPU usage is 0%, but when I try to open Windows Explorer, I can wait forever since the Task Manager shows Explorer as "Not running. It starts running when I go in with Task manager and End Process the Microstudio.exe.
I have un-installed Microstudio (which eliminated the MTU folder), reinstalled and re-registered Microstudio with no luck. I then uninstalled all four of the MTU programs and reinstalled them. All four were successfully re-registered. Keywrite, KHPro and Vogone come up fine; Microstudio is totally inaccessible. Oh yes, I ran Norton WinDoctor after the uninstall to check the registry and clean up any loose ends on my system.
Any ideas for what else I might try? Suggestions appreciated.