If you formatted it, you have wiped out any reference to ALL of its data, including the OS files. Unless you can use utilities to UN-format the drive, your best bet and easiest path forward is to re-install the OS. Do you have the Windows Install disk that came with the machine?
go down to the local computer guy's shop. the small ones. ask him to sell you a boot disk. he will probably charge you like 5 or 10 dollars or so. sweeten the deal by bringing a couple blank DVD's for him. sometimes if you got the DVD he will just give you one for free, or just charge you a couple bucks for the time it takes to burn one quick.
popatim has a VERY good idea there. You say you "formatted the drive". But when a manufacturer of a laptop places a recovery partition (semi-hidden) on the HDD, it is a SEPARATE Partition that is treated as a "hidden drive", and you would be very unlikely to Format that. They "hide" it so you can't destroy it by mistake. SO, IF you do have that feature on your machine (as he said, read the manual!), that is how you can restore the Operating System. You still will have lost ALL your applications and data files, but you say that does not matter.
Your recommended recovery tool did help me restoring my inaccessible and important files as I accidentally formatted my drive last weekend. It was totally free and efficient.
Thanks a lot!!!!!!!!!