Can somebody help a curious girl?

I had ubuntu 12.04 + win 7 installed, i didn't like ubuntu hence i deleted the partition.
But i forgot to fix mbr.
Also i cannot access the mutiboot option using f12 at startup.
So when i start ,i get the lenovo screen with f2 f12 options but none work,and then the screen shows
unknown filesystem
grub rescue-
with commands ls i get
(hd0) (hd0,gpt6) (hd0,gpt5) (hd0,gpt4) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) (cd 0)
and with set i get

may be because i had installed my ubuntu in gpt3 partition

can anybody fix this problem?

Reinstall ubuntu, boot into win7 and download EasyBCD, this nifty software will allow you to restore your mbr, rename partions and other cool stuff, it's a life saver.
Good Luck
Had this same problem. Easiest way to fix it is to get back into windows first. To do so, re-install ubuntu, then you should be able to re-enter windows as you were then doing before. Next burn a repair disc. Just search repair disc under the star menu. Burn to disc, then delete the ubuntu partition, boot with the repair disc and use that to fix the MBR using these instructions....

Vyger4 years ago
If you have a Windows 7 DVD (they don't always come with the system) you can boot from that and pick the option to repair the MBR. I forget where it is. Actually even a Windows XP disk has the option to repair the MBR. Boot from it and pick the repair consul instead of install then run the MBR utility. After fixing it this way Win7 might complain when you first boot it up and will want to do its own version of a repair. Just let it and everything should be fine after that.
RavensCraft4 years ago
There are two bootable CD's that I found to be very helpful one is called MBRtool and is available here:

The other is called GPARTED. You can get it here:

MBRtool: Choose options "Refresh mbr boot code"
                  and" wipe and clean track 0"

GPARTED:  Make sure boot flag is set for Win7 partition.

These two programs always worked for me when I
had XP boot problems . I haven't had any Win 7
boot problems so  I can't say for sure that it will work
for you or if you have to do something different.