Keyboard + Mouse sabtoging start up

[lord.enlil]

Stats: Macbook running Leopord, with 10.5.6

I've been sabotaged- some important files in my extensions folder got deleted (I think some USB files). My computer still works, but my mouse and keyboard are completely non-responsive; basically, my computer is paralyzed.
I tried booting in safe mode- didn't work. I get to the password screen and I can't move my mouse or use my keyboard. Even the Caps-Lock light doesn't turn on.
Interestingly, the computer recognizes the keyboard when it's still in boot-up mode. I only know this because it understands when I want to boot in safe mode (and I hold down Shift), and it even boots in safe mode, but I still can't use mouse or keyboard.
So- any advice, tips or suggestions from the pros?

[Giaguara]

How did those files get removed from your extensions?

First, reinstall the system (keep all existing data so archive & install), OR, if you have access to another Mac, try to install the Mac OS X 10.5.6 combo upgrade on it in target disk mode. As the files from /system have been removed or compromised, there is little point in trying with external keyboards or pram-voodoos. You need to get those system files back and in correct location, and the way to do that is either via a re-applied combo update via target mode, or via a reinstall of the system.

Then, make sure you have the login not set to automatic at startup. Keep the administrator account and password safe, so no access to any unknown user/workmates/kids/anyone else that should not be at your Mac in the first place. Set up also screensaver to require password to deactivate, and put on the screensaver when you are not at your Mac (activate from a corner, or set with timer etc). If someone else has a need to log in to your Mac, create them their own, non-admin account.

Third, make sure the people who did the sabotage in the first place have no further access to your Mac.