When your registry is corrupted, you have to reinstall Windows.
No other ways. If it's not too serious, you can to repair (that's
only available in XP). All other versions have to reformat.
As for files, you can try to repair. Most programs have a repair
option.
Just go to Start > Control Panel > Add/Remove Programs
Select the program and click on Change/Remove. When it prompts you,
select Repair.
Individual corrupted files like your Word documents, Excel
documents etc, I have no idea. Probably not, unless you have
hundreds to recover it.
