Help with soundcard upgrade

Hello all!
I just recently upgraded to windows 7 from XP and I am having some problems with my very outdated sound card. I don't know much about building computers. I know this is the card I currently have and it is clearly outdated and doesn't have driver support for 7. My motherboard is an Asus P4P800 SE with only PCI slots. The main problem with my card now is not that the sound won't work, it just won't play 5.1. Only 3 of my 5 speakers are making sound and when I go to settings it doesn't recognize that I have surround sound

I am basically just looking for a new card that will support all my speakers. Can someone please recommend a card for me that will be compatible with my computer and will have good driver support for a reasonable price? I'd really appreciate the help. Thanks.