The only way to find out if the operating system you want will work on that hardware is to try it out. I'm guessing that the reason you're asking this question in the first place is because you want to save money on hardware and this server you found (used, maybe?) looks too good to be true. As with most things in life, it probably is.
The main issues that I can think of with this kind of hardware are power draw, noise, and graphics. Even if it seems like you're getting a great deal, you might end up spending more money in electrical bills over the course of the time you own the server than you would if you just bought a new, energy-efficient desktop. Additionally, the cooling for server-oriented machines is designed to get maximum airflow and dissipate the most heat, without any regards for noise level. If you use the machine near where you're working with it (as with most desktop deployments), you probably won't like how loud it will be. Finally, if you think about how most server-class machines are used, graphics is not too important. Most servers run headless (without a monitor) and so do no graphics whatsoever. If you can stand the other two annoyances, the lack of modern-ish graphics might be a deal-breaker if you intend to run a graphics-intensive operating system like Windows.