|There will probably be a hidden partition on the hard drive, which contains a backup of the factory default Windows installation. If not, you could and should have made your own backup using the built-in Windows 7 "Backup & Restore" tool while your laptop was functioning properly. This creates a "system image" which you can use to get your system up and running again. Like many people, you just didn't bother and now you're clueless about what to do next.|
If a backup partition exists, pressing a specific key at boot time will give you access to the factory re-install option. Try F10.