I got the DigiTech RP150 for $100. I also have a combo amp (Fender Princeton 650 to be exact) and the effects kind of get cheezy on it, one of the reasons why is because it was $250 and i recieved it as a birthday gift. But let me get back on track, so I wanted a clearer sound so i turned to my pc. So i plugged my guitar in and the usb cable aswell. I installed the drivers and what not but I cant hear it play through the speakers. So I checked in the Sounds and Audio Devices Properties and went to the Audio tab and noticed it was using the RP150 as a soundcard but I wanted it to play through the speakers. So I changed the Sound Playback section to my pc speakers and changed the Recording Playback to RP150 In/Out. I opened up Guitar Rig 2 and tested to see if it picked up the sound and played it through the pc speakers but sadly it did not (I got my sound on my comp to work though). Alright so now for plan b, I took the pc speakers out of the computer and the connection between them and the comp was 1/8". So I checked the back of the RP150 and found no digital out to plug the 1/8" cable into. But I did find a headphones out and that fitted perfectly into it. So I tested it out a voila LET THERE BE SOUND! but there's a catch when I go to Guitar Rig 2 it picks up the sound but it also picks up the effects on the RP150 too, so the sound becomes garbled. I checked the Guitar Rigs settings and the Interface I chose was ASIO (DirectSound, ASIO, or Multimedia) and the Output I chose was RP150 ASIO (and that was the only option). I want to know how to stop the effects sound on the RP150 and just use it as a connection to the PC so I can use the PC's effects instead of the controller's. Funny thing was I tried using 'bypass' but that didnt do shit for me. It just blocked the effects from the RP150's and didnt pickup anything on the PC.

Please guide me through my dilema. I am a dumbass with computers.
long story...that is is a bit of a shortcoming when using USB, its mostly for recording and patches, not live playing. The RP live sound comes primarily out the 1/4 inch outputs to your AMP or preferably full range studio monitors. You PC will also be able to play directly though this same path.

The cheapest easiest solution is to take your RP headphone stereo output direct to your stereo line input of your sound card, and enable your sound card in audio properties. The quality difference is really not significant.