I think the -200 was included in MS Flightim 98. Since then, things hve moved on a bit, with the -300and now the 400 as the default Boeing.
There is a superb 737 6/7/8/90 as a flightsim 2004 add on from PMDG. No doubt there are hundreds of freeware addons at Smviation or similar if you are that keen on a 200. Will bet that you will get one in almost any livery you choose, too.
Conan