Thank you so much! Yes, I did purchase a used AM21, because, as far as I could tell they are difficult to find these days.
I have tried repeatedly to double reset my receiver, and I cannot get it to wipe the guide. I have tried unplugging it the second time while it is booting back up at each of the different phases in the process, as well as waiting until it is completely done rebooting the first time. In addition, even though I was able to get it to erase the antenna data yesterday when I started over, today, even with the antenna unplugged from the wall, and the USB disconnected from the DVR, the settings still displayed Sat & Antenna, even after rebooting the DVR several times. I am at a loss, but on the plus side, I have been able to get things to work, sort of.
In response to your request:
"Tell me what channels you are looking for, and where the incorrect guides are coming from (what city) and I will try and help you."
After following the instructions above, I was able to get the correct guide data for several channels, but I am still having trouble with the following:
*Channel 2-2 shows the same content as Channel 2-1, which is KTWO (ABC), but the guide is for KWGN (CW) which actually is on Channel 13-2, but everything is on one hour sooner than the guide shows. The guide for channel 13-2 is for WMAZ2, which is supposed to be CW, but it doesn't match any program data on the Casper CW as far as I can tell.
*Channel 13-1 is NBC (KCWY), but the guide is for WMAZ (CBS) out of Macon, GA.
*Channel 20-2 is a MyNetwork Channel, KTVD, but the guide for it is on 20-1, which is FOX. I have two Channel 20-1, and the first is correct, KFNB (FOX) with the correct guide.
Once again I really appreciate your assistance. I'm sure you can tell how technologically challenged I am!