Norton Internet Security bundled is full version software with 90 days free of charge update. There is no problem to use the software after 90 days. However, if you need the feature of LiveUpdate, please renew the subscriptions with the software vender, Symantec.
The 20-pin connector belongs to older ATX standard while 24-pin connector follows newer ATX standard. The 24-pin connector just the 20-pin cable with 4 extra wires to provide extra current. As long as your power supply can provide sufficient power to the motherboard, you can still use 20-pin power supply.
European Union had released the new Energy-related Products directive ErP 2009/125/EC to replace Eco-Design Directive Energy-using Products EuP 2005/32/EC in October 2009. The new ErP-Directive extends the coverage of energy-related products which includes not only products under the old EuP Directive but also those do not directly use energy such as showerheads, taps and water-saving.