If you're running Windows, I would also recommend downloading all avalaible updates. Windows XP is a prime example that should be at least running Service Pack 2. Windows Media Player and the .NET framework should be bundled with some of the Windows updates so this is the easiest solution.
Please don't quote me on these software requirements - they are just a collection of things I installed to get my sister's ancient laptop in a state where I could install Sky Broadband.
I'll post the hardware requirements soon but they can easily be found on the box that you receive from Sky.