Question Windows won't boot after easeus partition master didnt work. Doesn't even detect hdd

[themeiscool]

So the windows boot drive needed some space and there was a lot of space free on the other drives so I used easesus partition masterto give about 20 gb to the boot drive. I click apply and it tells me to restart which I do but the computer won't turn on. After the dell logo it says bootmgr is missing. So I create a bootable usb flash drive and try clicking the repair option. It says an OS must be selected. I click install windows instead and it says something like I'm missing an HDD driver. Tried installing a random one through the setup and it didnt work. Now I'm totally stumped.

That was my sisters laptop by the way and she has to leave in the morning and I need to fix it before that, it's already 1 am here. So I might be in a bit of a panic. Please help!!!!

 

[rgd1101]

make and model of the laptop? the bootable usb is from microsoft website?
so you just going to do a fresh os install?