Question: My laptop had Ubuntu pre-installed in it. I installed Windows 7 from USB by following the steps from [How can I install Windows after I've installed Ubuntu?](https://askubuntu.com/questions/6317/how-can-i-install-windows-after-ive-installed-ubuntu) 

Windows booted fine before I ran boot-repair. However, after I installed and ran the boot-repair from the Ubuntu live CD, Windows has stopped booting. Just a blank screen appears and nothing happens. What to do?

Thanks in advance.

Answer: 
Not an answer, but because that's too much for putting it into a comment.
You can read more on all of these popular threads.

* [Installing Ubuntu on a Pre-Installed Windows 8 (64-bit) System (UEFI Supported)](https://askubuntu.com/questions/221835/installing-ubuntu-on-a-pre-installed-windows-8-64-bit-system-uefi-supported)
* [How can I install Windows after I've installed Ubuntu?](https://askubuntu.com/questions/6317/how-can-i-install-windows-after-ive-installed-ubuntu)
* [Installing Ubuntu 13.10 alongside Windows 8.1](https://askubuntu.com/questions/399441/installing-ubuntu-13-10-alongside-windows-8-1)
* [How can I install Ubuntu without removing Windows?](https://askubuntu.com/questions/1366/how-can-i-install-ubuntu-without-removing-windows)
* [Why don't I have the option ''Install Ubuntu alongside with them''](https://askubuntu.com/questions/69481/why-dont-i-have-the-option-install-ubuntu-alongside-with-them)
* [Ubuntu install and dual Boot with Windows 8 UEFI](https://askubuntu.com/questions/193103/ubuntu-install-and-dual-boot-with-windows-8-uefi)
* [Ubuntu 13.10 installer/live fails to boot from DVD/USB on UEFI](https://askubuntu.com/questions/385159/ubuntu-13-10-installer-live-fails-to-boot-from-dvd-usb-on-uefi)
* [Install Ubuntu next to Windows 8 (UEFI dual boot)](https://askubuntu.com/questions/236787/install-ubuntu-next-to-windows-8-uefi-dual-boot)
* [Windows 8 removes Grub as default boot manager](https://askubuntu.com/questions/235567/windows-8-removes-grub-as-default-boot-manager)
* [Windows 8 deletes GRUB when booting](https://askubuntu.com/questions/447201/windows-8-deletes-grub-when-booting)
Just a suggestion, and that should solve your issues as long as you don't mind wiping your disk or having the trouble of backing up / moving files around between systems.

Best choice would be to wipe your disk, install Windows first using the first partition and then Ubuntu alongside it.