License Fix for 2007BPL00 Not opening only

Dear All,

Our system got crashed and installed SAP 2007PL00 . I want to upgrade to PL15 before that I applied a license and it is saying 'cannot verify the digital signature of the license file'. I downloaded license fix and i'm not able to open or run this .exe file.

What should we do not ?

can I install directly PL10 or PL15 and assign license. ? will system allow this or we need to install first PL00 only.

Kindly help. Proper response will be appreciated.

Rgds,

Kannan