Hello,

I am switching from an old computer under XP to a new one under seven.

I can't run any program with the SRV local WEB server, I get a message from Security of Windows : Server localhost at adress You must Log In! .... and an identifier and password is requested.

What can I do?

SRV does never show any login prompts. It's either OS or browser. First check this, then check the URL if it is browser, and check script behind the URL and server servicing the URL. Normally SRV does not service http://localhost/ -- it runs on 8080 port and URL would be http://localhost:8080/