i m sorry to say that enternet300 1.5c is not available these days in online.
instead of enternet , windows xp has a similar built in interface, its 99% similar to enternet
try configurin your isp using this simple procedure, configuring this interface is pretty easy compared to enternet.
so go ahead and give a try . i m sure u wont regret !
•Go to Start->Control Panel •Then Network & Internet Connections
•Then Network Connections
•Select Create a new Connection
•Click Next
•Select Connect to the Internet then click Next
•Select Set up my connection manually then click Next
•Select Connect using a broadband connection that requires a user name and password then click Next
•Type in your ISP's name then click Next (**See Note Below)
•Enter your user name as provided by your ISP.
for example: You might need to inlude your domain as part of your username.
[email protected]•Enter your password, then confirm it
•Select Use this account name
•Select Make this the default Internet connection then click Next
•Select Add a shortcut to this connection to your desktop then click Next
•Hit Connect
i guess this must resolve your issue :)