How do I change the network icon in the system tray?

I currently have the "window screen with the power plug."

I would like to change it to the Wi-fi icon (the three bars).

Is there a way?

Welcome to the Seven Forums

The icons for that are in the pnidui.dll in C:\Windows\System32 you can extract the ones you want to use and the import them back in where you need.
You will need a Resource Hacker of your chose.
You will need to take ownership, give yourself permission, rename the .dll and change it - look at post #6 it will show you how http://www.sevenforums.com/customization/179502-basic-networking-information.html#post1525656
Then restart the PC
Then you will need to do this http://www.sevenforums.com/tutorials/49819-icon-cache-rebuild.html
If you need help let me know.
Jerry

Just an update if you look at Post #10 of this thread http://www.sevenforums.com/customization/197187-modification-possible.html#post1656169 I had already done the modifications to that pnidui.dll let me know if I can be of any further assistance.
Jerry