Probably meant COA, the Certificate of Authenticity that ell you the version of Windows and the five groups of five letters each which is the Product Key. It is the Product Key that is needed for transfer of the license to another machine. With Windows 7, the “free” licensing of a Dell install disk on a different Dell machine stopped. One Dell Win7 product disk will only work on one Dell machine, no ther maker.
I think it is on the bottom of the computer. It may be legible.