What is a "yellow beer tin" with four letters?

[KILLERKIRST]

I need to my family's computer password my mum said she would tell mem but she forgot, now she's out and she won't come back for hours! I need to do an assignment!
So; if you know was a "yellow beer tin" is; and it's four letters and made up of letters like : D, S, A, C, X, Z, , E, W, Q etc on the left side of the keyboard.

 

[paige]

Beer tin s-i-g-n maybe?
idk... the question confused me. :O