Hello, please make sure you are typing this in correctly. Even for myself sometimes I get my B and 8 mixed up or just simple things like that. If you still cant get it to go, you will need to call Microsoft and try to get it working otherwise request them to re-generate you a new product key and they would email it to you. Only Microsoft can activate these softwares as we all go through there Servers.
To contact Microsoft Customer Service and Support, telephone
1-800-642-7676 (Customer Service)
1-888-725-1047 (Activation Dept.) 24/7
Microsoft Customer Service hours of operation: Monday through Friday, 5:00 AM - 9:00 PM Pacific Time Saturday and Sunday, 6:00 AM - 3:00 PM Pacific Time
BEST OF LUCK!GOD BLESS!