G’day,
I have just downloaded Audacity. I am using a Behringer USB interface UC6102. I can hear my backing tracks OK but I can’t hear the guitar which is plugged into the Beringher device. Do I have to download something e lse to make it work? 
Cheers
Buckshot
Do you have your headphones plugged into the UCG102 ? (I presume that “UC6102” is a typo?)
Yes mate I do
Buckshot
Yes it is a typo. Sorry never had the glasses on. 
Buckshot
Try adjusting the guitar gain switch (marked “5” in the manual page 10).
Ensure that the playback level from the computer is not too loud (you can probably turn that down in Audacity - if not, use the computer system sound controls.)
Ah… If that is the Beringher Book well I threw that out. Sorry 
Buckshot
p.s. I downloaded the combo box etc that came with the UCG. Would I have to remove that from the comp. I get guitar sound with that
Top tip: Don’t throw out the manual 'till you’re sure that you know what you’re doing 
The manual for the UCG102 is pretty small and can be downloaded - Google for it.
Sorry I don’t know what you mean.