I tried a failed dual boot configuration on a laptop and now I can't boot into windows. I get a message that no bootable device was found. If I go into the BIOS, it does detect the hard drive.

As well, I took it out of the laptop and plugged it externally to a computer. In disk manager I can see everything on it, but none of the partitions in it (unnamed, recovery and windows) are set as "active" or "boot".

Details of Disk

If I try to set the main one with windows as active, the selection is greyed out.

Similarly, if I use command prompt to use diskpart, it detects the disk, lists the partitions, but won't let me set the windows one as active. I get the message "the selected disk is not a fixed MBR disk. The ACTIVE command can only be used on fixed MBR disks."

Any help/ideas?


  • If this happened right after installation and you're confident you just did the configuration for the dual boot wrong (e.g some error in the partitioning or something else) I'd just reinstall and try again. – Leathe Oct 19 '15 at 5:06

If it's Windows 8 it may not have an MBR disk which is what it looks like. Instead it will have a GPT formatted disk which is what Windows 8 uses for UEFI by default.

If this is so, then it's also probably why your dual boot installation failed.

Check your BIOS settings and see if UEFI is enabled or not. Change the setting and retry.

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