Most Lenovo systems will have a reset to factory defaults option via a boot command. Something to check for on Lenovo's website.
When you say no disc drive, are you talking about not having a DVD-ROM to boot from?
If that is the issue, then you can create a USB bootable version of the Windows installation disc from which to perform a complete format here:
http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media
Another avenue would be to go to the hard drive manufacturer's, or Lenovo's website, for the factory reset tools for the drive/laptop.