Qos / Prioritizing Ftp / Scheduling Etc

Hi

I run a small business from Home. I look after 10 small Clients Networks/Servers and Backups etc.

I have an HP Proliant Microserver (6tb HDD's, 4Gb RAM, Windows 7 x 64 OS) which is setup for both a business FTP server (For Daily Backups from each client of the days emails, accounts etc during the night) as well as a Media Streamer which streams Movies via WiFi to a Mede8er in our Bedroom. The Customers backups are spread so that there is rarely more than 2 Simultaneous streams of 60-70kb/s and that leaves plenty of bandwidth for streaming 720p movies and documentaries to the Mede8er in the Bedroom.

Lately my ISP has offered after hours free bandwidth and instead of leaving my Main i7 Office Workstation on just to download YouTube Documentaries etc, I figured why not let the HP Proliant Microserver download the Documentaries etc as it runs 24/7 anyway and uses very little AC power. It should easily handle a few download streams.

The Question is as follows:

How do I set up the D-Link 2750U QOS (or the Group Policy in Windows 7) to prioritise the following order of data:

1. FTP incoming back-ups (High Priority)
2. WiFi Movies Streaming to the Mede8er in the Bedroom
3. Downloaded YouTube stuff, WIndows updates etc

Can this be done efficiently in the D-Link QOS settings, or in a Group Policy setting in Win 7 x64. Or do I need a managed switch or hardware device to prioritize the things in this order.

Any suggestions would be welcome. It just seems such a waste of power to have an i7 sitting there downloading every night (750watt Power supply) when the HP Proliant Microserver (150watt Max Power supply) is on anyway.

Dan