Im in a bit of a dilemma!

I have freeBSD installed a the minute on an old box which i was planning on using as my server OS but unfortunately, due to compatibility issues, ive had to rethink this!

So basically im looking for your opinions on a suitable OS which i can use!

I was looking along the lines of Windows 2000 Server, for compatibility issues only, but if anyone could give me a good alternative i would look into this.

Also does anyone use Windows 2000 Server, and if so whats the security like on this?

Thanks in advance for your thoughts!

Cheers