In order to play Tzar, your computer must meet the following criteria:
IBM PC or 100% compatible, 32 MB RAM
200 MHz or faster Pentium processor
Windows 95/98, Windows NT 4.0 or Windows 2000
4x or faster CD-ROM drive
Video System capable of displaying 800X600 Hi-Color Mode
The game was published in 2000, so it's sure to run on newer comps - I don't know about Vista/7 OPs, but it runs on XP w/o problems, it seems - feillyne. ;-)