There is a Youtube of a Optiplex 790 running classic (link below). The onboard graphics of the 790 is Intel HD 2000. Min specs required are Intel HD 4000. The game ran on low setting ok. Probably survivable as a side PC. But for pretty much the same cost you can get an Optiplex 3020 the meets min WoW Requirements.

https://www.youtube.com/watch?v=fqM_rSqzi3Y Classic on an Optiplex 790.