Yes you can export copies of the revlavent HKey\LocalMachine and HKey\CurrentUser regisrty entries just for the specific programs and then just re-enter them after you reformat, i.e for MS office you go into regedit, export the local machine key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office and HKEY_CURRENT_USER\Software\Microsoft\Office. If you just do a repair install of XP you may get away without re-installing the app as all the DLL's will be left in the system folders, but if you re-format the C then your still going to have to re-install the app, but if you run the registry exports after all your settings will be restored back to how they were which is a blessing for outlook..