If you are sick and tired of programs stealing the focus of your active window in Windows Vista and later, I developed the solution this weekend.
"Don't Interrupt Me!" gives you the same functionality you used to enjoy in Windows XP with the Power Toys plugin which unfortunately no longer works correctly post-XP.
All this app does is maintain the focus of your current window without any fuss. Once installed you will find it on your task bar with an option to enable / disable, and to toggle whether it runs at start up.
Download it for free here:
Let me know if you have any questions.