I currently run on Ubuntu 6.06. Today I installed Windows XP Professional Edition so that I could use some Windows apps that I can not run in Wine. I was intending to dual-boot, but instead the XP installation deactivated my Linux partition and I can not boot into it. Windows does not mention dual-boot or multiple boot anywhere, and I am unsure of what Windows' bootloader is anyway. Can anyone help me dual-boot with Linux and Windows (and preferably make Linux the default)?

Thanks,
Diomedes

You want to use this link, task B5. You should be able to use your Ubuntu install CD as the live CD.

Make sure that you mount and use the right partition. The example shown in the link uses /dev/hda4, which would be the fourth partition on the first IDE hard drive. You're basically looking for the root partition of your linux install. fdisk -l may help you figure out which one it is.

Thank you very much. I will try this out.

I got all the way to "grub-install /dev/sda" (sda is my primary hard drive where Linux is installed to sda1) and it says, "/dev/sda: not found or not a block device"
What does this mean? What exactly is going on?

Dear it is very easy to use Dual boot with linux.

Just first install Windows, and then install Linux - UUbuntu 6.06.
As then Grub will every time ask you that what you want to start?

pl. for more details steps installtion, google it.

or just ask us any specific thing, i will reply you.

Thanks.
With Warm Regards,
Ashish Barot.

For linux-india: Yes, he can start over and do what you say. It will only take a few hours.
Let's see if we can fix the current setup first........

for Diomedes:
From the initial post, I infer that you could not get into Linux. How then are you doing grub-install? (Live CD?)

Assuming that you can get running on some kind of Linux, do "fdisk -l" (as root), and post the output here.

If you don't have a live CD, get one---eg Knoppix
http://www.knoppix.net/

I know I could redo everything, india, but I already have a sizable Linux setup. I already have XP installed as well, and I refuse to go through that hassle again unless absolutely necessary.

Yeah, I am using my Ubuntu CD (which doubles as a Live CD).
Here is the output of sudo fdisk -l:

First you have to toggle the boot flag, so system uses proper partition to boot!
For changing the active (boot) partition, I used "parted", but I believe that You can do it with fdisk or some other programs. However in parted the operation is simple - I just entered command "flag", chose partition number (most probably 1 for you), selected "boot" flag and turned it "on". And that's it. Maybe you first have to switch off boot flag for partition 2, don't know, 'couse I had lost that flag completley. Then with "fdisk -I" check again to see whether the boot flag now stands for /dev/sda1.

I think that this should solve your problem. WinXP can't read Linux partitions so It couldn't delete grub files in your boot partition.

HOWEVER, if something is not right, make shure that you have {stage1,stage2,*stage1_5...} files in your /boot/grub directory, then chroot in /mnt/[your system mountpoint], run "grub", with "cat (" + "TAB" find correct disk and partition (my guess, it would be hd0,0 if you have only one HDD), enter "root (hd0,0)" (with TAB you can check whether it is your Linux partition, TAB should show folders located in / ). And if all is OK, then enter "setup (hd0)". Replace hd0 and hd0,0 with your own, if these are not correct. That's the way I have reinstalled grub tousand times...

OK--so Windows is in sda2 (on a FAT32 partition!!)

I assume that the grub config file is still in /dev/sda1---in /boot/grub (you can check with the live CD, by mounting /dev/sda1)

To install grub to the mbr (from the live CD):
This **should** get you back into Ubuntu. Then you may need to edit the grub config file to correctly point to Windows (since it is not in the first partition)

I don't think so. OP installed Windows after Linux and thus Windows took over the mbr. Once GRUB is back in the mbr, the boot flag on the Linux partition is irrelevant. (None of mine are ever on)

Well, mbr is quite simple code, which only points, where next bootloader is located. And WinXP MBR looks, which partition is active (boot flag), as far as I remember.MBR codes are different indeed, I have experienced that in some cases boot flag is required to boot. Turning boot flag on wouldn't kill anyone either... Of course, grub setup to hd0 will solve all problems.

EDIT: The bootloader that refused to boot without boot flag, was EXTLINUX. Maybe I did something wrong, but seting boot flag "on" solved the problem...

I have installed Linux maybe 100 times on various machines---never used a boot flag yet.

We're straying off-topic here, but here's my hunch: AFAIK, Windows has NTLDR in the boot sector of its partition--and the Windows mbr code points there. Linux does not do it this way.
Having said this, now maybe I'll go poke around and see if that's right......

I just did some checking, and this appears to be correct. It seems that partitions have 2 "empty" sectors at the beginning. For Windows, the NTLDR code is there. For Linux (at least ext3), they are empty---unless of course someone put grub or lilo there instead of in the mbr.

So.....does the Windows partition need a boot flag because NTLDR is there??

Well, I got it working. It turns out the problem was that I was going into the grub command line as a user. I entered "sudo grub" and it worked smooth as silk.
Thank you very much for your help, everybody.