If he's got a Lenovo sometimes those are finicky about getting into the bios. Let me understand this, did that system originally have Windows 8?
I'll look up that model and see you what they say about it, but what SIW2 says is correct about the fast boot - if that is activated you won't be a will to get into the bios for the UEFI partition or anything until that is shut off.
Okay I understand better now here is your machine:
http://shop.lenovo.com/ae/en/laptops/lenovo/g-series/g400/
And clearly it is a Windows 8 machine so it will have a partition containing a recovery environment for windows eight so you don't really want to use that.
And what I meant before about deleting that partition to me the only way that I can think of is for you to use a Hiren's boot CD-I don't know if I'm allowed to talk about that tool here? But you can stick the disc in the drive and boot up to Hiren's boot CD, and open "mini windows XP"
Once it loads you will see a link on the desktop for the Hiren's boot CD features and you'll see partition and recovery, you will find minitool partition wizard in there. You can use that to delete the recovery partition and then just extend the operating system partition to recover that space- or, you can wait until after you have installed the operating system.
But before you do anything you have to actually boot into Windows 8 and you have to turn on the Legacy boot mode. I can't going to the detail about how to do this but SIW2 can tell you how to do it.
This is a common problem with people wanting to install Windows 7 on an originally windows eight system, you should not do it all into you turn off any UEFI boot mode, you have to use the Legacy boot mode. And the first thing you have to shut off is the fast boot feature. once you set that up, then you can get into your system bios - IF the system has a key to press! some of the new systems don't have a key anymore, because you can only access that through the windows 8 desktop under advanced startup options in the settings which is in the Windows 8 side screen, whatever the hell it's called- move your mouse to the right and all that crap pops up on the side? Then move the mouse down to the bottom and look for the options, you can only get into it from there.
If you didn't do any of this and you have Windows 7 on it now, then you're basically stuck with a Windows 7 operating system but it still has the windows eight UEFI partition which you can't get to in Windows 7, so you might just have to wipe the whole drive.
However, it sounds like you found a workaround so as soon as you get Windows 7 reinstalled, make sure you turn off any fast boot feature. but I don't know how you can access your bios from Windows 7 because Windows 8 was intended to remove that feature from the system you can only get to it through Windows 8, so I don't know how you can get into your system bios with Windows 7 because the only access to that area was through Windows 8! It is pretty confusing...
