Why not change the sleep times to match what you want?
That is, why not set the screen to dim or off then push the sleep time to never or many hours?
While I do have another answer I found folk rarely write their own apps today so if you code in Visual Studio, post again.
Like the title says, i listen to live radio, but seeing as its not an actual software running, the computer doesn't recognize its running, and after 20 mins it goes into sleep mode. How can i prevent this from reocurring? It's a Acer All in one desktop. Acer Aspire Z3771 running Windows 7 home premium