Locked Out of Win XP Prof

I have a C/640. I for some reason decided to password protect my laptop and I have now forgot the password. It boots up normally, once it gets to the windows screen it asks for my password. I cant even use my programs because I can not remember the password for the Operating System. I read the FAQ on giving out passwords, but I am unsure if this is related to BIOS. Do I just put my Dell CD in and attempt to reformat the Hard Drive or do I contact Dell? Would rather not reformat but not being able to gain entry to my system tools is quite frustrating. Again I read the FAQ and I am unsure if the OS is related to BIOS Passwords.

 

Thank You in Advance.