Hi, I've read as much posts as I could before my eyes started to cross. I need help 
I have a Vista Home Premium, 32 bit .
I have a Realtek HD sound card.
I've tried everything I could think of. I went into the sound properties, keep tryin to configure it to play a 5.1 sound system ( i recently got a hold of a Altec Lansing ADA995) and it shows the option to set it to a 5.1 surround sound but for some reason vista wont let me select that option?
I'd appreciate any help

I have a Vista Home Premium, 32 bit .
I have a Realtek HD sound card.

I've tried everything I could think of. I went into the sound properties, keep tryin to configure it to play a 5.1 sound system ( i recently got a hold of a Altec Lansing ADA995) and it shows the option to set it to a 5.1 surround sound but for some reason vista wont let me select that option?
I'd appreciate any help