I recently tried to install windows 7 on my machine after not liking windows 8, but the setup failed and I couldn't get to the setup screen anymore, so I formatted the drive completely and tried to install windows but I can't even reach the setup screen? I cleared my cmos, checked boot priority a hundred times, tried a bookable usb and a disc, tried using a new hard drive, my friend even tried to install windows to the drive on his pc but nothing has worked.
Any help is appreciated
Had similar problem, windows 8 install / updates can somehow break your drive partition.
Take the HDD out, connect it with external adapter, do a complete format, and make a new partition on it.
If you dont have adapter anywhere around, you can connect it to your friends PC, via SATA and in Windows under disk management you can do everything you need.
Download a Linux disto of your choice as LiveCD/DVD, boot from that, start gparted (gtk based distros) or disks (fedora version), and kill all partitions/format your HDD with that (format as NTFS), it will save you the trouble of removing the HDD. After that, retry the windows install and it will work.
If you use Windows, you should always keep a Linux live dristro at hand to repair windows, like if you have malware, the best way to scan for and remove malware is with clamav from a linux live distro, best way to sort your partitions, etc... gparted on a livedristro. It's fast, easy, and effective, linux takes the frustration out of windows.
I used my friends pc to do a complete format and then installed windows to the drive using his pc (it was easier at the time) we tested that it booted and it did, but when I took it home and tried to boot from my pc I got BOOTMGR is missing, I messed about with boot priority and things but no success.
I made a bootable linux usb but when I plugged it in and set the boot priority, it didnt work. It just came up with missing operating system, I tried a couple of times but no luck.
Never mind it's sorted now the USB I had was fu-barred and I got a working windows 7 disc now