Is it possible to bott off a different hard drive if a different user enters his password and username?

Say I get on the computer.  I am the main admin.  I want to use both hard drives.  Say another user gets on I want him to use the Slave not the main drive.  Is there a program out there to do this if it isnt possible?  Would I have to install XP on 2 drives?  Could I use Windows 98 on the slave ?

Not sure what you're trying to do.

You can allow a user to store data on another drive and control access to that data with NTFS permissions.

Installing another copy of the OS would allow the user to boot the other drive but the first drive will still be recognized and accessable.

You can use Windows 98 on one drive, but that OS needs to be installed first on the root of C:  Then install XP on the other drive.  If your XP is NTFS, 98 won't be able to access the drive.

I thought it was pretty clear.  I dont want a user to access my hard drive.  He bought his own hard drive, I want him to use his on my computer.  He doesnt know anything about computers.  If there is a program to pick which hard drive you want to boot from at startup and mabey password protect a hard drive.  That would be perfect. If you guys dont know. Whats a good software website to ask? 

Thanks for your help.

It is possible (not real easy, but possible) to install Windows (whatever version) on each of the primary partitions of both drives. You would need to disable the first drive in the BIOS when installing Windows on the second drive, then enable it again. Then you can use a bootmanager to choose between either of them, so effectively you would boot to one drive and automatically hide the other one. You can even password-protect access to either of them (using for instance BootMagic). This system is relatively easy to set up, although it is not too difficult to circumvent. But it would fit your description.

That would be a possibility, but it requires you to change this BIOS setting every time you want to switch users again. And the other drive could still easily be enabled.  I also understand the other user already has his own disk. Removable disks are easier and more secure, but also more expensive. Certainly if you already have a suitable disk available. From that perspective I still suggest using BootMagic.