[FredZarguna]

1. Get the Windows® serial number off the the laptop.
2. Request new installation media from the manufacturer.
3. While you're waiting for that, on another computer, download a System Rescue CD here:http://sourceforge.net/projects/systemrescuecd/
4. Write that rescue "CD" onto a USB stick in bootable form.
5. Shutdown the laptop.
6. Boot the USB stick from the BIOS menu, and use the rescue CD to format the hard-drive. [You do NOT need to trash the HD as some here are recommending.]
7. When the install media arrives. Reinstall Windows®
8. Yes, it it highly likely that your WiFi password is compromised. Change from another computer, but only after you've reformatted the laptop, and do not log onto the network until Windows® is reinstalled.

[Hostage]

Thanks!