the hard drive with the fresh install of XP but the programs will all have to be re-installed as any dlls belonging to the program that the original instllation of the application wrote to the system32 directory will be missing as will any registry entries written to the registry during the program's installation and configuration.

Sorry, but the only workable "shortcut" to avoid re-installing everything is to create drive images when everything is just as yopu like it and after every installation of new applications and service packs, patches, etc. Acronis True Image is a good tool for doing that.