reinstalled XP and GRUB doesn't pick up on boot

[MarkH01]

I hosed my XP disk and had to reinstall. When I did, it nuked GRUB (I'm guessing since GRUB no longer comes up on boot and I had to format the disk).

My XP install is on the primary master
Ubuntu is on SATA

1. Do I need to reinstall GRUB? If so, how?

2. If I don't need to reinstall, how do I tell the machine to go back to using GRUB?

3. How can I access the Ubuntu install short of using a Portable OS disk?

4. Please keep it on a grade school level, I'm quite noobish when it comes to linux (but I'm learning)

Thanks folks.

[Elfy]

Yes you need to reinstall grub, should be simple

https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows