I have both XP pro and Ubuntu 6.06 installed on my drives. Everything is fine now.

Xp is installed on the primary disk while Ubuntu is on the slave disk.

Ubuntu was installed after XP,so GRUB has written on XP's drive MBR so as to multiboot.

The boot order is CD > Ubuntu > XP.

I want to format my XP drive due to a virus that has rendered it useless (i can boot to linux for now).

The question is :Will XP alter the MBR so that i will no longer be able to boot to Ubuntu?

If so, how will i make it multiboot again?

I dont care if i have to edit the contents of Ubuntu's /boot/grub/menu.lst or XP's boot.ini

as long as it wil be multiboot again

Thank you in advance.

Windows in any Version doesn't care for possibly installed non-MS systems, it simply overwrites the MBR. You will have to re-install GRUB. There should be something on the web that describes how to restore GRUB.

Will XP alter the MBR so that i will no longer be able to boot to Ubuntu?

Yes.

If so, how will i make it multiboot again?

If you are quite confident that the MBR and the first few sectors of the HD have not been corrupted you can make a copy of them with dd under linux and later restore them with either dd for windows:

http://uranus.it.swin.edu.au/~jn/linux/rawwrite/dd.htm

or the DSFOK toolkit:

http://www.ozemail.com.au/~nulifetv/freezip/freeware/

I don't remember how many sectors grub uses, but if you backup the first 63 sectors you are on the safe side.

An alternative could be using the grldr from Grub4dos to chainload Linux from the "normal" NTLDR/BOOT.INI:

http://grub4dos.jot.com/WikiHome

jaclaz