Question #1: Are all your hard drives sata drives? If not, then the boot order is dependent on what the bios is set for sata/ide... vs. IDE/sata...
 
#2: Do you get the Grub boot menu with no way to boot any OS, or just the word Grub on the top of the screen with no options?
 
#3: You told Ubuntu to install the grub bootloader on the MBR of the boot drive during the installation?
 
#4: You told ubuntu to just install on the new drive?
 
If Ubuntu was indeed installed on the second drive and the bootloader on the MBR of the original drive, then you can´t just remove the Ubuntu drive, as the reference files for Grub are on the drive that you removed. Grub then is unable to find these files that it needs to boot either OS.

Originally Posted By: danleffQuestion #1: Are all your hard drives sata drives? If not, then the boot order is dependent on what the bios is set for sata/ide... vs. IDE/sata...
yes, they're all SATA drives

#2: Do you get the Grub boot menu with no way to boot any OS, or just the word Grub on the top of the screen with no options?
I get the Grub boot menu that lets me select Ubuntu or XP Media Center, and they both work fine when all drives are connected. If I disconnect the drive with Ubuntu, I get a GRUB menu with some kind of error.

#3: You told Ubuntu to install the grub bootloader on the MBR of the boot drive during the installation?
I'm pretty sure it didn't ask me anything about GRUB when I installed Ubuntu - I was trying pretty hard to make sure it wouldn't touch the original C: drive with XP on it.

#4: You told ubuntu to just install on the new drive?
Yes, I selected the new hard drive when I installed it.

If Ubuntu was indeed installed on the second drive and the bootloader on the MBR of the original drive, then you can´t just remove the Ubuntu drive, as the reference files for Grub are on the drive that you removed. Grub then is unable to find these files that it needs to boot either OS.

I guess I'm looking for a way to get back to my original configuration before I installed the new drive and Ubuntu. I.e. I want (if possible) to remove the new drive and have the system boot into XP like before. I don't care too much if it's GRUB or the windows bootloader really as long as my computer runs without the new drive (it was supposed to be temporary).

OK, I was just yrying to see exactly where you were at. Answering these quesrions helped me to understand what you really did and what the bootloaders were doing, based on what drives were on the system.
 
What happens if you try these steps exactly as described in the article?

I did the exact steps twice and I get the same error (Error: Failed to add the selected boot entry to the boot list).
The only thing I changed is that when it asks me for the load identifier I put in "Microsoft Windows XP Media Center Edition" instead of 'Microsoft Windows XP Home edition"

What message do you get after typing in bootcfg /rebuild directly after entering the recovery mode? No other commands, as suggested.
 
Do you get something like;
 
"The windows installation was successful"
"Total identified windows installed: (number)"
 
or straight to the error message?
 

I have a workaround for the GRUB problem, though most people who have been working on the problem a while have probably already discovered it. Just leave a MS boot disc in the CD drive and let it time out. Then the machine should either boot to windows or present a boot option screen. I know its a pain in the ass, but I have tried most of the fixes mentioned and I have not gotten any of them to work yet.

There is never a need to settle for using the CD all the time.
 
The issue is that folks decide to install Linux next to XP and allow Grub to overwrite the boot sector of the primary drive, then try to either just delete the Linux partition, or in the case above, remove the second drive that Linux was installed on.
 
The problem with this, is that by just removing the partition or second drive, you remove the Grub reference files on the Linux partition to boot the system.
 
The solution in these cases is to rebuld the MS MBR. The method depends on what version of Windows that you are using. XP and Vista have different methods of creating the MBR, thus different methods are used to recover the MBR.

I just did the same thing.I had xp/vista and server 2003 and tried suse 10.3 but it didn't like my raid. I knew better but tried it anyways and thought maybe i could get something so it would recognize my raid config but it didnt. I redid xp and server, it didn't recognize vista though since I repaired from xp. I will just start from vista and they have a fix startup after repair options, but that WONT work to get rid of GRUB.
The . C:\WINDOWS
CD ..
FIXBOOT C:
FIXMBR
BOOTCFG /rebuild
routine worked, as i did for
D: and E: as well after fixing all 3 MBR's then I did the bootcfg /rebuild.