BOOTMGR missing error 3

[ew125]

this error message pops up when i try to turn my laptop on, im then told to press alt, ctrl, del which then just loops it back to the error page, i cant press f11, or the 0 button when i start the computer as iv tried to see if i can just put it back to factory settings, im only able to press f12 and f2. I only have my friends laptop for tonight so any help would be MASSIVLY helpful. (I dont care if i lose all the work on it, if that's easier )

 

[ew125]

I responded but it doesn't seem to have posted, no i don't have the disk unfortunately, i tried to do the thing where you restart the computed with a windows 7 disk in and that didn't work either Any ideas are greatly appreciated, im not very tech savy, but im not bothered about losing anything on the computer just really need it to get onto the internet for the next 3 weeks.