What parts of Qlab are you looking to replicate? There are a number of media server programs available for Windows.
...with the caveat that it hasn't been maintained or updated in about six years. It's a great program and I still use it occasionally on my Windows machines, but it definitely needs a little extra care at this point. MP3s will play, but you may run into sound quality issues with certain encodings--variable bit rate in particular is something I've noticed as problematic. WAV files are safe as long as they're 16b. If you have a WAV that's not playing correctly, then it was probably encoded at 32b. There are some other odd quirks here and there, but mostly it's consistent in whether it works or doesn't work. I've never had a situation where it seemed to work at first, then behaved differently during a show.