Frozen Desktop

Hi everyone...hope someone can help me!

My PC has been infected by SPYSHERIFF, and I need help on how to remove it. I've read the proceedures on this forum, and it's pretty well set out....READ & RUN>Disable And Enable System Restore, but I CANNOT righ-click 'My Computer' as the desktop is frozen!!! (I'm using my old system to use this site!).
My 'new' system with the problem and running (WindowsXP) shows the desktop with the unwanted icons and the SpySheriff Control Panel showning 323 threats found. In the background of the desktop a 'Restore my Active Desktop button is visible but click anything and nothing happens?

Queries:-
How can I download the software tools that will be needed?
Do I need to be online to delete the spyware.
Will all my files mp3s, documents be lost for good?

The SpySheriff 'program' seems to be running (Slowly!?) as a Security Warning has just popped up! Would clicking to buy the spyware removal program acually work?


Please help!