Installing a HDD
Your other option would be to buy a DVD writer and burn the files to a DVD-Rom.
Before you copy the data you need to clean the PC as you may copy the infection and reinfect your clean install when you copy the files back or access them, I'd suggest doing the following submit a hijackthis log
here.
How to submit a hijackthis log
Download Hijackthis
Try running the following from safe mode
Sysclean you'll also need the virus template file from
here lpt***.zip
or
DrWeb CureIT
Also try installing and running
A2 Free and
Ewido
I'd also run
Spybot and
Adaware
If your using Win2K/XP run adaware/spybot from "safe mode with command prompt"
At the C:\ prompt type the following:-
cd\
C:\progra~1\spybot~1\spybotsd.exe /autocheck /autofix
cd\
C:\progra~1\lavasoft\ad-awa~1\ad-aware.exe
NB there's also a thread
here by the same person.