Not at all a BTB problem, except I wish to use it with BTB. Close your eyes Mr Moderator please. Downloaded 3D simED, to put a few corrections onto my track, and it will not run. I know there are lots of BTB bods who use 3D sim and I wondered if anyone had an idea as to (the eternal question) -Why? Put the same question onto'The Pits' forum = 0. Had ideas from Dave Noonan = came to 0. Probably another program interferring? Took out all usb devises - Switched off firewall and antivirus, and ran machine in safe mode =came to 0. Do not get any error messages just - "3D simEd has stopped working. Microsoft will try and find the answer". Microsoft doesn't. I can run 3D simEd version up to 1.8 fine but as soon as I try any version 2, it refuses to open. If it comes to it I can run the prog on my wifes laptop but thats a bit of a pain and I would really like to find out, why.