Think Tank seems to work beautifuuly on XP. However, I have had the following problems. I used a function key to mute the sound. This popped me out of Think Tank. I also accidentally held down the shift key and this popped me out of Think Tank. In both cases, after dealing with Windows error messages, the file I was working in was trashed. What can I do about this? I love Think Tank and want to be able to use it reliably on my laptop, particularily, since my old Windows 98 system is getting on in years. Are there things I should know about running a DOS program on XP?

You might want to run it from DosBox or a similar DOS emulator. There are posts about such programs in the forum, which a search should bring up.
Manfred

Thanks for the information.