I opened up a Windows XP computer and checked. There are no problems with XP and SetEdit that I can find.

Open your first instance of SetEdit. Select your channel file and load it.
Then click on New in SetEdit and select Comaq HD 100. This will open your second instance of SetEdit.
Next, open your second satellite file. You are now able to drag and drop between the two files.

Information on how to do this is in the instruction manual that I posted earlier. I found out how to do this by carefully reading the instructions. EB