[Mobhack]

Windows 7? - are you trying to run it in full-screen mode?

As noted in the Game Guide, Full-screen mode requires the running of a script that nukes Windows Explorer in Windows 7, in order to allow 256 colour full-screen mode. No other Windows version needs this (Windows 7 "Aero" thinks it owns the 256 colour game palette).

Full-screen mode is a leftover from the MSDOS roots of the game, and is obsolete. Once explorer is nuked, you cannot alt-tab to other Windows applications - in Windowed mode, the game and other Windows applications coexist.

And as noted in the Game Guide, the script may be able to restore explorer or it may not, depends on your system. otherwise you need to restart Explorer yourself in Task manager. Which is described there in the bit on the Windows 7 explorer-nuking script, IIRC.

Try running in the recommended Windowed mode at desktop resolution. This is how the game should be played on modern monitors - It's faster than the obsolete 256 colour mode on modern video cards which prefer 32-bit colour mode. That should resolve your problems, if you have been using the antediluvian 256 colour full-screen mode.

The other thing to try is a windows version other than 7, of course.