No Surround Sound via HDMI

I have Windows 7 32 bit running on an Aver Aspire Revo 3610. The "sound card" is a High Definition Audio (I couldn't find further details on it). I'm trying to get surround sound on my Samsung reciever by plugging in a HDMI cable from the computer to the receiver. I get sound, but only through 2 speakers. I tried to adjust the settings in control panel; I don't have an option to select 5.1 surround sound under the HDMI device. Most forums I've found say to just select that option and I would love to, if only it was there!

I've updated Windows, made sure my drivers were up to date. I'm stuck. Any help would be greatly appreciated. I was told and read that I can do at least 5.1 surround sound with this computer...

cwirick, welcome to the Seven Forums.

I would start with checking you have the Nvidia HDMI audio driver installed,

NVIDIA DRIVERS 1.00.00.59 WHQL

Also is the source 5.1/surround or stereo only? If it is stereo then an upmix somewhere along the line is required to get surround sound.

Also found this thread here,

Acer Aspire Revo Owners Thread - AVForums.com

No idea if the answer is there, but seeing as it is 34 pages long I would hope someone has brought it up.

Ok, so updating the Nvidia driver worked. I've got surround sound going through the HDMI. The only problem now? 5/6 speakers are working. The rear right speaker doesn't play sound. I tested it on the configuration menu of Windows and it tests just fine. Is there a setting I need to change? I can't figure out why it's just the one speaker not working.

Also, most of my sources are 5.1 so I don't have to upmix. But I do have some stereo sources, how do I upmix them.

Thanks so much!