error message on digital edition 4.0 on authorisation of computer

Hi

Please help. I have downloaded adobe digital edition 4.0 to read my ebooks on. however adobe cannot be authorised on my pc. Every time I enter the adobe id and password and click on the authorise button, an error message appears.

This gives me a problem as I cannot download my ebooks onto adobe and read them to.

How can I solve this , please help