Unlikely unless you had the address book outside the os and did not format. Have you tried a search for *.pst files or *.wab files? A tip here for anyone contemplating doing any kind of alterations to windows itself, save a back up of; my documents, address book and if using outlook the pst files(windows address book in outlook express)at the very least. You should consider also copy the "program files folder" so that you have a reference to what you had installed previously. Remeber if anything is in the windows folder it may be lost.