My computer has administrator password as well and i have forgotten both administrator and my user password. now is there a way to bypass the log in screen by typing some words from the keyboard?

No.

If this is a dell, they can get you in. There are ways to get your password.
You can also reinstall the OS because you have the disk, or do a system restore
before you set the password.

I won't explain the ways to extract the password, as I have heard this a thousand
times from people who have stolen computers.