I finally got mine working by turning off the Windows Firewall and my antivirus. After that the channel scan worked great. Update: I changed out my hard disk and did a recovery of a previous XP backup. I had not installed HDHomerun yet, but did have GBPVR installed. I turned off the firewall, then installed HDHomeRun and ran its setup utility. HDHR then asked if GBPVR was my viewer, and I clicked ok. HDHR populated the list in the channel scan for me. You do not need to do a scan in GBPVR - all the channel info should be there. Hope this helps someone.