disable write in file system
 

How would I go about disabling write permission to the whole hard drive for a particular user?

You could add the appropriate "umask" identifiers to the file /etc/fstab

Hello,

probably a bit harder, 'cause with ar1's method "user" will always be able to write its own /home directory... unless you also set "umask" permissions correctly in user's config file and then lock these files (for example chattr +i ~/.bashrc)

Oliv'

Ok, i know this might seem a bit involved, but is there any way to COMPLETELY secure a linux system so that without the root password, the user can not do anything malicious? Also, If I do edit the fstab, where would I put the user name. I've read some things about it, and the five columns provide nowhere for individual access rights.

I think that's impossible :( Of course you can secure your system so that anything malicious will never happen... but you can't be sure. For example a new kernel flaw appear, the attacker exploits this flaw and gain root privileges :cry:
in the fouth column... with the options "umask=" or "user="... see man mount and the corresponding FS for more info

Oliv'