Won't accept my log on password

Hi. A few days ago my apartment had a brief electrical power surge, not enough to turn everything off, but it froze my emac. I had to unplug to restart. Ever since, it is refusing my password. I've tried about 500 times. It will only let me log on as another user, and it always logs in to this user. WHAT TO DO???? What would cause this? I tried resetting the password with my 10.2 disc, the disc will mount on the desktop, but won't open to utilities when i press c or option during start-up. When I open the disc and go to reset it says not running from the CD. This is a copy disc, not an original. Could this matter? I can't choose start-up with Cd because it asks for the password. Why the heck would it not be accepting it all of a sudden? I tried the command-option-f-o key during start-up to turn off firmware, but that didn't seem to do anything. The mac help site says it will ask there for your password but it didn't. What to do? Can anyone help? I can't change my login either as it again asks for my password. I am the admin and this is the password for that. I am running 10.3.7. I am unable to access any of my files...that sure takes the fun out of things. Any advice appreciated!!! Thanks in advance. (PS yes i ran out and bought a brand new much better surge protector)

I can't use System Pref to start up booting from the CD, it is locked, and to unlock, it asks for the admin users name and password, this is the password in question. There are 3 users on this computer, one is the admin, which is me, this password was set by the people i bought the mac from, i've just kept using it, (its worked a million times before), this is where all my files, bookmarks, pics etc are. Then i made another account, one is also me, one is my girlfriend. This is the one I am logged onto now, i can also log out and log into my friends account, it accepts her password, then i can log back to this one. Apparently i had the computer set to automatically log on into this acc't, without realizing it ( i never shut the computer off- i use sleep mode). I can not reset this to automatically log on as the main admin account, because it is locked, and to make any changes, it asks for my admin name and password. I have held the C key down for the entire time, it still boots up normally, then i see the disc mounted on the desktop, i can double click it, and it opens just like any regular CD. It says Mac OX 10. I can then get to utilities, and to reset password, but then it says this can only be done from a disc in the CD. ????
I bought the emac used, i think it came with Classic 9. It was upgraded and running 10.3.7 (thats how i bought it). The only disc i have is a COPY disc labeled 10.2. I have no Panther disc.
I actually wondered about the keyboard. Obviously it is working because i am using it to type this. It says on the back Pro keyboard. is there somewhere else I could check?
What do you think happened? Could i have a virus? When i go to Syst Prefs i can still see my account there, but most of it has red negative signs in front.
About 2 weeks ago we had a power outage a couple times. My computer shut off, and when i restarted it logged into this acc't, acc't #2. At first I panicked, thinking everything was wiped out, but then i realized i could log out as this user and log back into my main acc't, and it accepted my password, no problem.(This happened more than once recently). Yes i should have reset it then to log in automatically on acc't #1, but i didn't know about that at that time. Why in the world would it stop accepting the password now????
I know with Windows you could actually go into the tower and remove the battery, if all else failed to reset the password. Does mac have any feature like this? Should i go buy a new copy of Panther, or perhaps borrow someone's?
Appreciate all the help.