Hey everyone,
I haven't posted here for a while, but I was just wondering....on a linux or windows 2000 (or any other multi-user OS), is it possible for a normal user to install a program to read raw disk sectors to bypass any security protecting files on the OS?
No, of course not.

A normal user can install the program to read raw disk sectors, but it won't work unless you're Administrator (or root, or similar).

Like other posters said, with the ability to boot off an alternate source (CD, floppy etc), an attacker can read any file on the disc which isn't encrypted (*and* plant a keylogger or trojan to get at the encrypted stuff)

Unlike what the other posters said, NTFS does not make it significantly more difficult to read (or write) protected files - many tools are available. It will only stop the most l4m3 script kiddies (and not even that is guaranteed)

The trick is to ensure that users cannot bypass the normal boot process
- Password protect the bios setup
- Boot from the HD only
- Password protect the bootloader (where necessary - for example lilo)
- If physical security is a real problem, put the machine in a locked box.

finally

- Never log on to a workstation in an unprotected physical location with a network admin or any other kind of privileged account
Because if the machine was compromised, it could have a keylogger on.