Cannot boot Windows 7 under dual OS with Debian 8
 

I have recently installed Debian 8 (netinstall) to replace Debian 7 on a Windows 7/Debian 7 dual boot system. Exactly the same partitions have been used and Windows 7 has not been touched. The Installer detected Windows OS and asked if GRUB should be put in the MBR, after selecting a Yes answer it asked if this should be on SDA1 or on the USB stick containing the boot image, SDA1 was selected and at the completion, the USB stick was removed to reboot. UEFI was already disabled before install.

Now I am unable to boot in Windows 7, the only option is Debian 8 or Debian 8 Rescue. I suspect I need to change GRUB.

Can anyone suggest a solution? There must be one on the Internet but I cannot find it.

Just as a coincidence, I have exactly the same problem (installs done on the previous day) on another laptop purchased a few days ago which has Windows 8.1 but this does not really matter as Windows will never be used on that one, UEFI had to be disabled on this laptop and, if my recollection is correct, the Installer did not even detect Windows 8.1, I hope Bill will be happy to know 50G of HDD have been wasted for Windows on this laptop.

Thank you for your help

Try re-running the GRUB configuration (dpkg-reconfigure grub-efi-*), and carefully choosing your responses. Make sure what you think is highlighted is, etc. GRUB installed properly, or you wouldn't be getting any options. Something is going wrong with the Windows detection perhaps.

Way back long ago when I still dual booted (I haven't done so in a long time, however), on occasion my Windows partition had to be mounted in order for it to be properly added to GRUB's menu. I never figured out why. Try giving that a shot.

If windows is booting in uefi mode, it would be better to install debian 8 in uefi mode.

rblampain,

First try booting from your Debian 8 live DVD or USB flash drive and follow these instructions to repair Grub2:

http://www.howtogeek.com/114884/how-...ntu-wont-boot/

If that doesn't work, I would do as colorpurple21859 suggests, select UEFI and follow this guide:

Dual boot W8 (UEFI) & Ubuntu 14.04:

http://www.dedoimedo.com/computers/d...-8-ubuntu.html

Thank you for your replies.

No, Windows has never booted in UEFI mode with Linux installed but it has without Linux and the laptop on which I need Windows has Windows 7 with BIOS enabled, not UEFI, I do not intend to upgrade Windows on that machine because the only Windows software I need is some Australian government software that works under Windows 7 but not under Debian.

I will try goumba's suggestion (dpkg-reconfigure grub-efi-*) but I do not have enough experience to figure out what "*" stand for and I do not want to proceed blindly.

Run, as root:

When I was running in legacy mode on my Debian laptop, that was the package to be reconfigured.

If this doesn't work for you, run

to narrow down which package to reconfigure. It will not be either of the common packages.

rblampain,

This W7 (non-UEFI) dual boot with Xubuntu guide should help you:

http://www.dedoimedo.com/computers/d...7-xubuntu.html