I all accounts are password protected and you dont have the passowords..
Download EBCD (Emergency Boot CD)
You boot with it. you now would enter the NT password utility. Then you can enter the SAM file. Here is where your passwords are stored as hash.. You can now enter the user name and it will ask you for your password. blank it out and save the sam file..
Whole process will take you about 5 minutes.
EBCD also has a bunch of utilities that you can use for disk checking, formatting, editing, file browser.. almost every thing you need in an emergency.. hence the name EBCD