Right now i'm running jsut win xp on my computer. I have a second hard drive and would like to run Linux on that so i don't have to partition and can enough space for linux. Is it possible to install Mandrake 9.1 on a second hard drive and still dual boot. And if so how do I go about this? Thanx.

absolutely. You may have to relegate your win drive to primary slave. One way or the other you need to get the computer to boot off the linux drive. Lilo will happily point at a windows partition if you have one and mandrakes install will set that up for you assuming it's there during install. The only tricky thing is making sure that you tell it to install on the correct hard drive.

hope that helped

Actually I think it's best to leave Windows as Primary Master, because it both prefers that location, and it's how your working system is atm.
I have linux on a second hard drive and by using the custom partitioning install option (very obvious) I can format and use my second drive for linux as well as having Windows work fine.

If your XP drive is NTFS, you might want to make a small FAT32 partition to be able to write to something Windows can read. Linux cant write directly to NTFS just yet, but can read it fine though.

the way I have done it is I have left them both as masters but only have one conected at a time .... its a bit of a pain disconecting one and conecting the other but its the way I like it

I have a 2 HD system. The primary HD is XP, the second is split between Win98SE and Mandrake. I use lilo as the boot manager with no problems. The tricky part of setting this scenario up, was getting 98 to install on the second HD, but lilo makes it think it is on the first.

Yep the bootloaders Lilo and Grub can fake drives being switched to please windows, and there really is no need to physically swap drives unless you want absolutely no change to the drives' Master Boot Records (where the bootloaders reside).
Plus you can chain them, so you can pick the OSs on one drive or start the loader in the MBR of another, and then pick from it's list of OSs.

The easiest way to dual boot Linux and any Windows system using two drives, especially if you already have windows installed, is to use the second drive as the Linux drive. With Mandrake, the only thing you need to do differently is install to the second hard drive (which should be called hdb in the install routine assuming you install it as the slave to your Windows drive). When it comes time to install your boot loader, install it to hda (the first hard drive) and either lilo or GRUB will detect your windows installation an set it as an option in the boot menu. With XP (and other NT based windows) you can also have windows boot menu list Linux, but it is a bit more work. My work machine is set up with windows controlling the boot since it is the "recommended" operating system, but I have been booting Mandrake since ver. 7. One thing to do to avoid problems: before starting your Linux installation be sure to go into your machine's bios and disable any boot sector virus protection so the install routine can write to the boot sector of hda. You can re-enable it later after you have both operating systems booting. (If you do re-enable it you will have to disable it any time you are upgrading the Linux kernel, but this doesn't happen often so I would.)