Reinstalling XP

I'm due a reformat of XP and normally I back up my settings to transfer. However, in this last cycle of xp i have become infected with annoying popups and probably some adware. If i export and transfer my settings, am I at risk from transfering registry entries or anything else that will compromise the installation?

why not just do a system restore to an earlier time than the adware started happening. Then do the reinstall.