So I have a large external hard drive and an old laptop that I want to setup a media server on. I want to be able to access all my media over wireless in my house. What software for windows is best for this. I will be using itunes for most of my media.

You have alot of choices. I don't have enough to go on from your description to be extremely precise, but here are a few.

If you run Vista, you can use WMP11, but with caveats. Probably best to look at Slimserver, Twonky , SageTV, Monkey Media or Orb. As far as server, you may be able to run Windows Home Server, but it will require at least 2 gig RAM to stream well.

Ben