this is the solution that ended up working for me... i got it off a review for a product on amazon. give it a try...
<<<<<<<These instructions are for Windows 7 64-bit specifically
Do not even take the disc they give you with the receiver out of the bag... it's worthless.
Google "xbox 360 controller pc driver" and the first hit should be a link to the official Microsoft page for the Xbox 360 Controller for Windows.
Under the Support tab you can download the official software, which does work with this HDE 360 Receiver and gives you the on screen display and shows your battery level remaining, etc, just like on the 360 console.
Once the official software has been installed...
Plug in wireless receiver to your PC
Open Device Manager
Right-click "Unknown device" > "Update Driver Software"
"Browse my computer for driver software"
"Let me pick from a list of device drivers on my computer"
Highlight "Show All Devices" > Click Next
WAIT... it may take a second to load if your PC is slow
Under Manufacturer select "Microsoft"
Under Model select "Xbox 360 Controller for Windows Version: 2.1.0.1349 [8/13/2009]"
Click Next
When you get prompted for the Update Driver Warning click "Yes"
When you right-click and open Properties on the receiver in Device Manager, open the Driver tab and you should see the following:
Driver Provider: Microsoft
Driver Date 8/13/2009
Driver Version: 2.1.0.1349
THAT was the key for my installation on Windows 7 64-bit, the default driver it was finding before was dated 2006 and did NOT work even though it did recognize the receiver.
Once your receiver is working, click the sync button on both the receiver and your wireless 360 controller and you should see a pop up from your System Tray about "USB Input Device" was detected... your controller is now synced.
If you open the Game Controllers menu under Control Panel you should now see the 360 receiver listed, and you can click Properties and verify visually that all buttons, thumb-sticks, etc are working properly and you can even perform calibration of the analog inputs should they need it but I wouldn't bother unless you notice an issue.
For $12'ish shipped this is an excellent value IF it keeps working long term I will be very happy. Microsoft did not stop making the official receiver, they just decided to stop selling it individually. You have to buy the bundle with a new controller, which was foolish of them in my honest opinion and why you see all these knock-off's online.
I had previously been using my PS3 controller on my PC via a software called "DS3 Tool" by "MotionJoy" which you can look up online as well... even works with BlueTooth supposedly. A good alternative if you already have a PS3 controller because no dongle is required and the "DS3 Tool" software is completely free.
I hope this review was helpful for anyone hesitant to give this a try or having issues with the receiver driver installation.
EDIT - 01/06/13 - I've been using it for a few months now with zero issues, thing works like a charm. Also thanks everyone for responding that these instructions were helpful, and I took note of some suggestions and modified the above instructions to reflect that the official M$ driver / software should be installed before you do anything.
I've been using this dongle to rock the new Steam Big Picture mode and it works perfectly...

>>>>>>>