The "cost nothing" requirement might be the issue here... However radmin might work as mentioned here there is a cost free 30 day demo version, so maybe this would be an option for you.
Another option which you might test is RemoteFX:
Microsoft® RemoteFX™ is included as part of the RD Virtualization Host
role service, and it enables the delivery of a full Windows user
experience to a range of client devices including rich clients, thin
clients, and ultrathin clients. RemoteFX renders content by using
graphics processing units (GPUs) that are present on the server and
then shared across multiple virtual desktops. RemoteFX renders a range
of content including DirectX and all types of multimedia, and it is
optimized for LAN-based networks.
This is part from Windows 8 and Windows Server 2012 and included in RDP (Remote Desktop Protocol). It is also backported on Windows 7 Enterprise when installing the RDP 8.0 update. So if you are using Windows 7 home or something like that it will not work as you need Windows 7 Enterprise (or Ultimate) as outlined by Microsoft.
Additional it looks like that the machine where you wish to use RemoteFX on must have at least Windows 2008 R2. You can follow this howto here which explains how to enable RemoteFX on that server so that you can then connect to it via RDP (from your Windows 8 Enterprise / Ultimate Workstation with RDP update). This YouTube video here also showing some limitations from RemoteFX but it make use from the Hyper-V stuff which isn´t really required in a simple setup as mentioned before. You might wish to check also this question here for additional infos.