I have been running dual boot Windows XP and Slackware for years but I recently changed things up a bit a "broke" something.

Windows XP is on it's own 250GB HDD. I installed Windows 7 on a seperate 74GB HDD but it appears that it installed the bootloader over top of the Windows XP bootloader on the 250GB HDD. Both OS's booted fine and that point. Then I partitioned the 250GB HDD into 150GB and 100GB leaving me 100GB to install Ubuntu. I told Ubuntu to stick it's bootloader on the 250GB HDD thinking everything would work like magic although there appears to have been a little bit too much magic. Normally Slackware will allow you to manually edit your Lilo config file during installation and add all your OS's but this didn't happen with the Ubuntu install.

After the install there were 5 options in the bootloader menu (at this point I am not even sure what bootloader it was using). Ubuntu, Ubuntu ("safe mode?"), memtest, more memtest, and Windows 7 (bootloader? it wasn't just called windows 7 but something like Windows 7 bootloader, I have only booted once and I am writing this from Ubuntu right now). I tried selecting Windows 7 at that point hoping that it would bring me to the Windows bootloader which would allow me to select from Windows 7 and Windows XP but the screen just went blank for a second or two and then sent me back to the same screen I was just at.

So a quick Google of Ubuntu bootloader led me to believe I was using Grub and I needed to look for the /boot/grub/menu.lst file and edit that but the file wasn't there. Then I tried running grub but I was informed it wasn't even installed. I thought maybe I would have better luck with Lilo but that wasn't installed either. So I installed Lilo and ran liloconfig but I was told that fstab gave a UUID that led Lilo to belive I wasn't using an ordinary block device and I should go fix that and come back afterwards. In fact the only thing in fstab was the ext4 partition with Ubuntu and the swap partition even though I have 4 sata drives installed with 6 separate partitions.

At this point I am pretty lost. Most of my Linux work is done in Parallels now on a Macbook so I haven't had to mess with the bootloader in years and when I did it was all on Slackware which to me is set up quite a bit differently than Ubuntu. I would be pretty sick if I screwed up and took out 3 OS's with it.

Any help would be much appreciated. I am particularly curious to know how Grub will handle booting both Windows OS's when Windows appears to be doing it with one bootloader.

From Ubuntu
Grub2(grub-pc) is simpler
It also doesn't have grub menu.list.
If you have sudo priviledges and grub2
"sudo os-prober"
"sudo update-grub"

Well that wasn't a very helpful post EDDY1 - obviously grub2 was already installed and had done the os-prober.
The fact that it isn't correct is unsurprising - for either Ubuntu or grub2.

That is working as "designed" for Windows - laughingly called "dual boot". Later versions (since Vista , maybe Win2k) replace the prior version - in the partition of the prior release. So you continue to boot that. With both grub and lilo you merely chainload to that and let the Windoze loader handle things.
Looks like grub2 is trying to chainload to the wrong partition.

Do you have a boot-able system at all - and if so, what is in the MBR, lilo or grub ?.

This led me to believe he had lilo:

This is reason I suggested grub2.

I am curious, is your Slackware on a separate hd or on the hd with XP?

To get windows 7 to boot will need to add an entry similar to this to your /etc/grub.d/40_custom file and rerun sudo update-grub. This is what my entry looks like.

Windows 7 usually creates two partitions during installation. The first partition is the boot partition and the second is the system partition. My windows paritions are on the second and third partitions of my first hard drive. I don't know which drive/partitions windows7 is on in your setup so /dev/sda2 maybe /dev/sdb1 and (hd0,2) maybe (hd1,1) or some other variation.