No OS found after changing GRUB, please help !

Hi all,

I have to admit I have a problem I caused myself. I installed Ubuntu 14.04 on my computer next to a Windows XP/7 installation. I had to install XP before I could install W7 on this system although it is a full version of W7, so no upgrade version.

What happened?
I had a running system with W7 installed. I installed Ubuntu 14.04 in a dual boot setup. I wanted to change the Linux install to another distro, because I could not change Ubuntu as I wanted. I saw some youtube-movies, where it is showed dead simple to change grub and remove Ubuntu. I followed this, but Grub did not change. I tried another movie, in which the install disc of W7 is used to repair in dos with the commands bootrec /fixboot and bootrec /fixmbr. Using the /fixboot command I got an error message I unfortunately can't recall.
Ahter this I wanted to restart the system and got the message "No Operating System found".

I hope you can help me getting this computer back to live, as I need it every day.

If you need extra information, please ask, because I'm helpless in this :(


Noob Whisperer
Hello and welcome to the forum.
Have you tried booting from the installation media and just running the "Repair your PC" option and doing the "Start Up Repair"?
Some have reported that it might be necessary to perform this operation as many as 3 times before it's successful.
After you have tried that and it still proves unsuccessful then you might want to go back to your bootrec.exe command prompt and follow up
/fixmbr and /fixboot with

Thanks for this reply ! No, I didn't try that. Before screwing up more I thought it might be better to call in some help from people who really know ;) . I considder myself as an experienced Windows user, but this problem seems to be a little too large :eek:.

I'll try this tomorrow, thanks :up:

Just watched the link you provided about the use of bootrec. There I saw something I forgot to mention in my problem discription.
  1. Put the Windows Vista or Windows 7 media in the DVD drive, and then start the computer.
  2. Press a key when you are prompted.
  3. Select a language, a time, a currency, a keyboard, or an input method, and then click Next.
  4. Click Repair your computer.
  5. Select the operating system that you want to repair, and then click Next.
  6. In the System Recovery Options dialog box, click Command Prompt.
  7. Type Bootrec.exe, and then press Enter.
Step 5, I don't see an operating system to choose here.


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Damn, I tried to do a startup repair for 7 times, unfortunately no result.

When I try bootrec /fixboot the system responds:
The volume does not contain a recognisable filesystem.
Check if all the necessary filesystemprograms are loaded and if the volume isn't damaged.

Is a fresh install the only option now?


Just started installing W7 again :(:mad::eek:
At least my computer is fast again. Maybe it's better next time not to install a Linux dual boot on the same harddrive in another partition.



Noob Whisperer
Is a fresh install the only option now?
That is a difficult question to answer at this point. The changes that may have been made to your hard drive by installing Linux and how the Grub boot loader may have altered the drive configuration may only be determined by removing the drive from the current system and attaching it to another computer and examining that particular drive in disk management to determine what volumes may remain, what there contents might be and which partition is set as "Active" and where your current Boot and System partitions might reside.

I just read your subsequent post, while I was writing this reply.
Sorry to hear that you had to resort to a re-install of Windows.
Beware when installing various dual boot options especially Linux Distros. They can and do make radical changes to the drives boot manager. You may find that in many instances using something like a Virtual Machine Manager, like
Might be a better and safer environment to explore Linux

Yep....I learned the hard way myself....from that point I'll never dual boot windows with Linux on the same drive....Now, on separate drives... the MBR and GRUB are not an issue as they are on individual HDD's (not a partition).

Thanks for this contribution !

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