Hi,
I don't think you installed NAP, because it is not a server role. Did you install some services under NPAS (network policy and access services)?
When you can only reach the local network but not the Internet using a static IP address, but it works with DHCP this indicates one of two possible problems:
1) Your default gateway is incorrect
2) You DNS server settings are incorrect
Make sure your default gateway is the LAN address of your cable router and you have valid DNS server addresses when configured for a static IP.
If you need help to troubleshoot this, please provide the output of ipconfig /all and route print -4 when using DHCP and again when configured with a static IP.
Thanks,
-Greg