Change/add paper size to printers

I tried to add a custom paper size to my printer(s) by going to the printer

properties and preferences found the stock sizes but could not add a new

custom size.

Searched the KB found #838298 which said I needed to be a administrator, I'm

logged in as the administrator. 838298 went on to say must have SP 2 well I

do have SP2.

So How do you add a new custom paper size to my printer?

Thanks

Terry