Depends on your version of Windows. If you can press F8 a bunch at boot and get into Safe Mode, then you're not totally rooked.
The file can probably be found on your Windows cd and might be named hal.dl_ (just renamed it)
If you boot off your Windows CD and try to install to C: again, it should also prompt you to do a repair instead. (Not repair console - repair reinstall)
If you don't have a Windows CD and just have a manufacturer restore disk, this usually wipes the hard drive.
Either way, do a Scan Disk once you get your computer working again.
The good news is, your data's probably still there, and a tech savvy friend/family or a computer shop should be able to pull it off onto DVDs or an external hard drive.