If you run that command, you sir, are f*cked.
Not really. I already did that
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
C:\Documents and Settings\Adminl33t>rm -rf /
'rm' is not recognized as an internal or external command,
operable program or batch file.
C:\Documents and Settings\Adminl33t>
dd is worse, though. You can really mess things up with dd.
or rescue deleted data or recover from failing hard drive. Or make perfect clones. Guns don't kill
people data, DD does!
Like overwriting the first 512 bytes of the disk
Enjoy
Windows have pretty much standard MBR so if it was known to be a clean and standart installation, the MBR can be manually recreated with hex editor. Or copied from other MBR and adjusted for partition size. Things are little worse with full disk encryption, you need a backup to restore loader and key data if it is located there.