I locked my hardrive and cant get into it now.......how can i unlock it

Need more information. How did you lock it? In the BIOS?

Assuming you did this in the BIOS you will need to enter the BIOS by hitting F1, F2 or DEL while the computer is booting in BIOS. Sometimes you will see the BIOS key noted on the bottom of the Boot screen. On the first BIOS screen check to see if your HD is listed. If so go to the BOOT screen. On the BOOT screen check the boot order. To move the HD to the top click on the HD and click on the "+" key to move it up of select it if you get an options window. In the BOOT SETTINGS screen click on the HD to varify that the correct HD is listed. If more than one HD you can move the boot drive up by using the "+" key or options window. Check your other settings. When done hit ESC and go to the last screen and select to SAVE and Reboot.

If you locked yourself out at the Windows Password screen. If you are using Windows XP Home, reboot and hit F8, F10 or F12 during BIOS boot. Select SAFE MODE. When Windows open go to the Control Panel - Users and delete the users. This will remove the passwords. Close windows and reboot computer. Windows will now start and open without passwords. If you are using XP Pro you will need to take the computer to a Tech who will have a Password Disc to clear the passwords.