Hi, I'm purchasing a computer soon and I need to know if the specs described above is okay for gaming, not great but enough to play at least call of duty 4, or a little lower than that, thanks
What is it, a Dell Optiplex 755? Most likely has integrated graphics. You may be able to play on low quality, but otherwise you'll have pretty poor performance.
You can run it, wont play very well though. You could put a GTX 750TI in it and it would greatly improve performance, but ideally you want quad core CPU