have run spydoctor hardware but still cannot change desktop - delete off web-based hijack not available

Greetings - I'm working on a laptop that had a run-in with theAntiSpywareMaster scheme. In the process, it also received a flood of spyware and the desktop was hijacked and replaced with a busy background and a foreground of links to vulgar websites.  I have now run Spydoctor and gotten rid of various risks from low to elevated; I've removed various versions of  AOL and the system is markedly improved.  However, I still cannot replace the desktop.  The system is currently disconnected from the internet and I believe if I connect it again without removing this last item, the reinfection will start.  

When  I attempt to select a new desktop image,there is no response on that screen; the desktop image currently selected is represented by an AOL icon and the word 'desktop'.  I cannot select it, delete it or replace it.

Any assistance would be appreciated.