[Tech] Can't Boot into OS

[Nanor]

So I decided I'd dual boot Ubuntu and W7 on my laptop. All was well until the next day I turned on my laptop and was informed no operating system was found. I installed Ubuntu again as it was the only OS I had. I installed it, restarted and was presented with a boot menu allowing me to choose Ubuntu or Windows 7. I booted to Windows 7 and everything was as normal. The next day I turn on my laptop and again I'm told it can't find an OS.

Halp?

 

[Iron_fist]

sounds like you didn't make whatever partition you have the boot loader on bootable.

 

[Nanor]

Oh, how do I do that?

 

[Iron_fist]

use fdisk from the linux install and then check that the partition that has the boot loader has a * next to it otherwise there should be a menu option to make a partition bootable

 

[Nanor]

Bleh, right. Laptop has just ran out of charge and I won't have a charger 'til Sunday. Here's the story:

I have 3 partitions:

• /dev/sda1 - called dell. It has the flag diag.
• /dev/sda2 - called recovery. It has no flag.
• /dev/sda3 - called OS. It also has no flag.

/dev/sda3 has 4 sub-partitions. I've tried fdisk /dev/sda3 -a then selecting the first partition. Printing the partition table again shows a star beside the first partition which has says boot loader in the description column. I write the changes and reboot but it still tells me I can't find a module.

/sda 1 to 3 each have about 4 sub partitions each. Can I make all of these sub partitions bootable and let it cycle through?

 

[elDiablo]

Have you got any funny settings in your BIOS? Like only boot from 1 partition? A partition which no long has any boot information on, maybe?

 

[Haven]

Empty CD drives, unplug all USB disk/stick/sdcard based peripherals (this includes phones and printers) and attempt to boot again When installing ubuntu choose to allow grub to install as the master boot loader. This will install it into /dev/sda rather than a sub partition so it "will" get called as long as you have your BIOS set to boot from Disk.

 

[Nanor]

Cheers Haven, I'll give this a go when I get my charger back.

 

[Nanor]

Okay. I installed Ubuntu and I think everything is working. While I'm in Windows is there anyway for me to check, seeing as I'm familiar with the OS?

 

[Spicypixel]

Windows and GRUB do not get on well from the perspective of windows respecting it or being able to see it. Worst comes to the worst just run the Win7 setup disk and get to the repair console and type fixboot and then fixmbr. That'll overright the boot sector with the windows boot loader.

Just off topic, if you wish to avoid this if you salvage it all and ubuntu is just for testing and such, WUBI makes the whole process less painful by using a loopback partition on the windows drive.

 

[Haven]

Windows by default doesn't read most of the linux file systems (it can do ext3 but thats about it). Linux can read (and write) to all the windows file system types though.

In short unfortunately Linux is great for looking at Windows but not so much the other way around.

I'm assuming that you see the Grub menu with choices to boot into Windows or Linux on boot. If thats the case and both operating systems are booting fine then everything is indeed working. Try them both is the best way to check

As a counter point to spicypixels suggestion to run WUBI. Linux installs fine on USB devices, there's nothing wrong with installing it on that 8GB USB stick that you may have lying around and then booting to USB should you want to try something different.

 

[Iron_fist]

As a counter point to spicypixels suggestion to run WUBI. Linux installs fine on USB devices, there's nothing wrong with installing it on that 8GB USB stick that you may have lying around and then booting to USB should you want to try something different.

exactly, the new router i built runs entirely off an 8GB stick, the only small issue it has is write speeds aren't all that great, but otherwise it's awesome

 

[Nanor]

Back to the same damn problem. Was running fine for a while allowing me to boot into whatever OS I chose but I'm getting "no module found".

I've tried using a System Recovery disk which does not recover my system. Anything I can try from the cmd prompt?

 

[Ronin Storm]

Does make me wonder whether you've picked up a rootkit. Reinstallation wouldn't avoid that.

 

[Nanor]

What can I do?

 

[Spicypixel]

Could be an actual hard drive physical error, in which case its pretty terminal.
http://www.dban.org/
burn iso, boot and nuke the drive.
Try again

PS. Back things up to external usb storage using a live ubuntu disc or something.

 

[Nanor]

Is there anyway I can just tell the computer to boot from the CD using the cmd prompt with the recovery disk?

 

[Nanor]

Oi did it! So far anyways...

Turns out that Dell computers are a bit of a twat when it comes to dual booting things and deletes grub. Basically by doing this I've fixed it for now. I'm sure there's something pre-installed from Dell which will break it again but I'll investigate further.