Uninstalling grub more comlicated than it seems bet you cant figure this out

dmanlikespie · 12-13-2010, 11:41 PM

ok here is what happened i had unetbootin and put unbuntu on a flash drive and i got tired of booting then not having a wireless driver installed every time i would boot so i took that os and used the preset install linux button to install on to an opposing plash drive that way i could save the wireless driver well in that process it wiped the windows mbr and installed grub well it also made it to where i had to have the flash drive even to boot from the hard drive and i am not able to use the whole boot recovery crap because there is no disk drive and im not able to boot windows from a flash drive because grub says "revove all devices o media" or something like that and to make it even better in windows XP os it is a limited account so i can not install windows on a partition and reset the mbr that way either any help or ideas would be greatly apprecieated thank you.

Bruce Hill · 12-14-2010, 12:40 AM

Say what?

Since it's hard to understand your run on sentences with no punctuation, let me assume.

The MBR is just 512 bytes at the start of the disk. So, if your disk is sda, then

Code:

dd if=/dev/zero of=/dev/sda bs=512 count=1

will put zeroes on those first 512 bytes.

dmanlikespie · 12-14-2010, 07:28 PM

Quote:

Originally Posted by Bruce Hill

Say what?

Since it's hard to understand your run on sentences with no punctuation, let me assume.

The MBR is just 512 bytes at the start of the disk. So, if your disk is sda, then

Code:

dd if=/dev/zero of=/dev/sda bs=512 count=1

will put zeroes on those first 512 bytes.

Sorry i was in a hurry. I am not gifted with Linux at all. on the other hand i am very gifted with windows.so could i have some more explanation please?
I was trying to say that i had unetbootin. I used it to create a boot-able version of Linux. well it worked fine until i found out i needed a wireless driver installed. i got the wireless driver installed and realized that every time i booted Linux the wireless driver was wiped. so on that boo-table version of Linux there was an install option, so i used another flash drive to install to. Well upon that install it erased the windows mbr and put on grub and grub works only when the flash drive is plugged in upon boot. I am not able to just use windows recovery because the computer its on does not have a disk drive, and grub does not recognize the boot-able flash drive of windows.

Bruce Hill · 12-14-2010, 07:39 PM

Hey, I'm not a grub type of guy, except when fishing for bream; but, if
you edit your grub menu.lst or grub.conf file such as:

Code:

# The next four lines are only if you dual-boot with a Windows system.
# In this case, Windows is hosted on /dev/sdc1.
title Win7
rootnoverify (hd0,0)
makeactive
chainloader +1

Adjust those values for your Windows location and you should be able to
boot into Windows with grub. Granted, grub is not as intelligent as lilo,
or as easy to use (think /dev/sdc1 in lilo vs. hd0,0 or whatever in grub)
because grub does not read your drives the same as BIOS and Linux.

If you can't get grub to work, and can't install lilo, then you need to
Google for how to fix the MBR from a flash drive.

TobiSGD · 12-14-2010, 07:41 PM

Quote:

Originally Posted by Bruce Hill

Say what?

Since it's hard to understand your run on sentences with no punctuation, let me assume.

The MBR is just 512 bytes at the start of the disk. So, if your disk is sda, then

Code:

dd if=/dev/zero of=/dev/sda bs=512 count=1

will put zeroes on those first 512 bytes.

Don't do this, it will destroy your partition table !!!

The correct code is:

Code:

sudo dd if=/dev/zero of=/dev/sdX bs=446 count=1

You have to replace the sdX with the identifier for your harddisk. You can get the identifier with GParted or by typing

Code:

sudo fdisk -l

.

The dd-command will erase the bootloader GRUB from your harddisk, so that you can start from your Windows flash drive and repair your installation.

dmanlikespie · 12-14-2010, 07:58 PM

Quote:

Originally Posted by TobiSGD

Don't do this, it will destroy your partition table !!!

The correct code is:

Code:

sudo dd if=/dev/zero of=/dev/sdX bs=446 count=1

You have to replace the sdX with the identifier for your harddisk. You can get the identifier with GParted or by typing

Code:

sudo fdisk -l

.

The dd-command will erase the bootloader GRUB from your harddisk, so that you can start from your Windows flash drive and repair your installation.

I feel so useless not knowing some of this. Are you saying harddisk as the harddrive that windows is installed on or the flash drive that is required for boot that has linux on it?

dmanlikespie · 12-14-2010, 08:09 PM

and i can boot into windows just fine because it shows up in grub but i just want windows mbr back.

TobiSGD · 12-14-2010, 08:16 PM

To get you MBR back, you have to boot into the Windows recovery console. Most times this is done by booting into a Windows install medium and choose the repair option. If using Windows XP you have to type the command

Code:

fixmbr

into the recovery console, if you use Vista or 7 the the command is

Code:

bootrec /FixMbr

You have stated, that your computer isn't starting from your flash drive with Windows on it. You should be able to change the boot priority in your BIOS, so that your computer tries to boot from USB first.

dmanlikespie · 12-14-2010, 08:24 PM

i have tried booting the flash drive many times and changing the boot order but i am not able to get it to boot.

TobiSGD · 12-14-2010, 08:34 PM

Have you been able to boot that Windows flashdrive anytime in the past? I mean, are you sure that it is bootable?
If so, you should be able to boot from that device. You can try to remove grub with the dd-command, and see if that works to get the usb-drive working, but I doubt so. Be aware that you will not be able to boot Windows at all, if you do that and you nonetheless can't boot from your Windows flashdrive.

dmanlikespie · 12-14-2010, 08:44 PM

Quote:

Originally Posted by TobiSGD

Have you been able to boot that Windows flashdrive anytime in the past? I mean, are you sure that it is bootable?
If so, you should be able to boot from that device. You can try to remove grub with the dd-command, and see if that works to get the usb-drive working, but I doubt so. Be aware that you will not be able to boot Windows at all, if you do that and you nonetheless can't boot from your Windows flashdrive.

Well i have just extracted the windows xp .iso file to the root of the flash drive. i belive it is i will try to see if it is on my desktop real quick.

TobiSGD · 12-14-2010, 08:53 PM

It will not work to just copy the contents of the disk to the flashdrive. However, I am not sure, if Windows XP is able to run the installer from an USB-disk at all. It may be the best and simplest option to get a USB-CDROM drive, may be you can borrow it somewhere. Or you can try to boot from the .iso-file with Grub4DOS.

dmanlikespie · 12-14-2010, 08:56 PM

well i do have vista .iso and 7 .iso

dmanlikespie · 12-14-2010, 09:01 PM

well the only thing i ever get is "remove disks or other media. Press any key to restart" and ive thought about getting a usb cd rom drive its my last resort id like to fix it with what i have on hand. If i can not i shurly will.

TobiSGD · 12-14-2010, 09:24 PM

Quote:

Originally Posted by dmanlikespie

well the only thing i ever get is "remove disks or other media. Press any key to restart"

That is, as I mentioned before, because of just copying the files to the flash-disk doesn't work. You also need a bootloader on the flash-disk.