Yep, you can. If your PC has a digital output (either coaxial or optical) and your receiver has the matching input, I'd recommend using that. I have my HTPC connected to my receiver with a digital coaxial cable, and I also have a Powermac G5 connected with optical.
If your PC doesn't have digital outs, you can always get a cable like this:
http://www.lg-internet.com/catalog/i...202%20RCAM.jpg
Stick the one end into the headphone jack on the PC, the other end into your receiver, and you're all set.
If your PC doesn't have digital outs, you can always get a cable like this:
http://www.lg-internet.com/catalog/i...202%20RCAM.jpg
Stick the one end into the headphone jack on the PC, the other end into your receiver, and you're all set.