Disk full, code 1120

[jbre]

I'm a 74 year old guy that dosen't speak "computerez." Yestreday I purchased a 120 gig West. Digit. for back up and it included retrospect software. I hooked everything up, stuck in the CD and selected manual transfer. It seemed like all went well. Later I decided why not put it on auromatic - so I did. The next thing I know I get a message saying something about can't locate the drive or error code 1120. Now, I have decided to read the instructions - which I don't understand anyways - to see if I can undo what I have done. As far as I can understand, there is nothing I can do - or can I? I went to "MyComputer" and clicked on drive F, the external West Dig I installed, and when I click on properties for drive F it shows that it is full. What do I do now coach? HELP please. Any and all advice will be appreciated. I am running Win XP on a Dell 4500.