If you formatted your disc, you have erased your hard drive and its operating system.
To reinstall your operating system you will need a CD/DVD drive. You can get Windows or Linux. You can download a copy from another computer and burn it to CD. Linux is free, and an easy version to start with is Ubuntu. You can download it here: http://www.ubuntu.com/GetUbuntu/download
Download the ISO file from that link, and burn it to a CD or DVD. If Windows doesn't recognize the format of the file you downloaded, you will also have to download a program burn the disc, such as Nero. You can download Nero here http://www.nero.com/enu/support-downloads.html
With the disc ready, turn on your laptop and put the disc in. It should automatically boot from your CD, if you hard drive has been formatted. If not, restart the computer and press F2 at the very first screen to enter BIOS. It will look like a blue console. In BIOS, go to Boot Options. Use the + and - keys to make the CD/DVD drive boot first, by moving it to the top of the list. Save and exit (F10). Your computer will restart and boot from the CD. Press a key to boot from the CD and follow the instructions to install your operating system.
If your laptop does not have a CD/DVD drive, you will have to use a USB drive to install your operating system. It is a bit more complicated to do, but you can find instructions here: