computers accessing some of my drives

OK, I have done this abut three times now but this time I topped myself. I am on a sort of high profile network, and realized the other day that there were computers accessing some of my drives and straming god knw what off my hard drives. I turned sharing off, and like a MORON decided to monkey with my permissions.

Here's what I did:

selected my various drives, and through the get info pane, changed the permissions by removing the Everyone group, changing other various permissions and then applying to all emclosed folders. I did this on 2 computers simultaneously so I took out my 2 main workstations in one fell swoop. Basically what I am having to deal with is a total failure to launch my computers. The OS volume wont boot. If I put a disc into the drive and boot using the C boot command, nothing happens. I started again using the startup selector boot command, and a giant padlock icon appears with a login window underneath it. I removed EVERY drive and my install CD and used the startup command and it still appears. Is this stored in the PRAM??? I tried resetting the motherboard by hitting the reset button and removing te friggin battery. somehow both computers are both locked up internally?!?!? Any ideas... other than dont do stupid s*%t. Both drives are backed up, but I can't even reinstall my OS from the disc. It wont recognize my discs as a startup volume. Terminal commands, tech programs with a good startup partition, loaded gun? Anything helps. Make sure if you respond you start with "Dear Idiot". Thanks..

DeLa

BTW: Specs are

Computer 01
Quad Core Intel Xeon
Mac OS 10.6.8
9 Gigs Ram

Computer 02
Mac Pro 8 Core Intel Xeon
Mac OS 10.6.8
14 gigs Ram

Thanks.