Restoring a lenovo laptop with windows 7 to factory settings

If you look on the laptop next to the power button should be a smaller key with orange symbol on it. press that instead of the power key.
It should run one key recovery giving you the option to restore the Os.

Press f11 rapidly after starting.

http://www.youtube.com/watch?v=j7G93cWDVqo

That is indeed the button. Pretty nifty little utility.

@bata_51: Are you sure the recovery partition is still intact? If not, you will not be able to use the one key recovery method.

In some models, like my Lenovo IdeaPad Y470 from 2011 the little button is the same color as the chassis. It's called the "Onekey" because the Lenovo has the Onekey Recovery utility used to either install Windows from the hidden partition, or from recovery DVDs that you manually create (if you created them).

I generally recommend making a recovery disk after you install all the updates and any programs you always tend to use. That way if you need to do a recovery again you can save several hours trying to update the default install of Win 7 / 8 to where you want it to be.

For me, I created my recovery disks after spending around 20 - 24 hours updating, patching, modifying settings and installing programs. I don't want to go through that trouble again.

Here's a video on how to use OneKey:
http://www.youtube.com/watch?v=eKyjsv5B8E8