How to sync data on two hard drives? [duplicate]

Possible Duplicates:
Keeping folders synced between several machines
Synchronize Laptop and Desktop
Which is the best application to Sync two folders?

That's it. What can I use to keep my hard drives in sync on Windows?


I do it this way,

make a file called sync.bat

XCOPY t:\somefiles f:\copy /D /I /S /C /Y
XCOPY f:\copy t:\sometimes /D /I /S /C /Y

XCOPY copies files from one directory to another, and then the options I set do the following; assume it's a directory, copy the newer files, overwrite the older files, and don't ask if I want to write over it every time.