Restore complete HDD .dmg to new (bigger) hdd

I upgraded my lappy HDD from the stock 120GB HDD to a 320GB one, but before I did, I connected it to my desktop and made a complete .dmg backup of it (as in, File>New>Disk Image From Diskx). I had a Windows 7 partition, which Windows 7 made me extend upon it's installation to support the Windows recovery partition (or at least that's my guess), so now it won't mount in OS X when I open the .dmg>I can't use Disk Utility to restore it.
I've tried using dd, but I haven't figured out exactly how to tell it to copy the partition. I really haven't used the mac partition any further than what's in the backup, so restoring the whole DMG would be fine, but I need some help with the command.
1st: I would have to "decompress" the DMG, right? So that dd can copy it block by block...?
2nd: how exactly would I input the dd command parameters so that it copies the whole DMG to the new HDD (connected thou firewire or, if necessary/if it will speed it up drastically -which I think it will, internally thou SATA), taking into account the the new hdd will be bigger? If it would make it easier, I could just copy it "as is" (ie, leave the difference in space free), boot into Windows, use Windows to make it's own backup, then delete the Windows partition from OS X, make the OS X partition bigger, recreate the Windows partition until the end of the drive, and then use Windows to restore it's backup. This would take centuries, so I'd rather just use dd

Thanks in advance.

dd if=/dev/rdisk3 of=/dev/rdisk4 bs=32m worked for OS X (1st partition without counting EFI, 2nd if you do count the EFI one) but Windows (which I can select to boot from) says "Missing Operating System". I'm currently booting into the Windows repair environment, to see if I can fix it.

c'mon, you command line locos, anyone know the right syntax?
I'm running TestDisk on it now, I don't know how much good it's do me, but maybe it will re write the MBR code right or something...