Urgent help needed - System Halted!

hi guys, i recently put a password on DOS on my dell dimension and my brother decided to try and guess the password.
when i try to type in the correct password my keyboard does not work and any key i press doesnt come up, but if i press <ENTER> it says "Number of unsuccesful attempts: 7 or more.

Syste Halted! Must power down.

so it wont even let me try the password, the only key that seems to be doing somthing is the enter key.
Is there any way to fix this problem and it is a very urgent matter.

Please note i dont have very much knowledge with computer inside but any elp would really be appreciated.

thanks in advance for all your posts

After a long wait, you can try again and your legal password will work.

ive waited weeks, still wont let ....

i got it sorted, i needed to open up the comp and move some thing fro 2 sticks to to other sticks and it worked and removed he BIOS password.

it was on the dell support site.