Tarq57 and mixture are very probably right, but you can at least learn a bit about the nuts and bolts of the operating system by playing with things such as the registry and control panel.
You can also type msconfig in the run box and go to the start up tab and un-tick any programs you don't recognise
Also be careful what you back up onto DVD before you re-install everything it would be very easy to copy a copy of the virus onto the DVD and transfer it to the new install don't copy any .dll , .exe , or .ini files