Sample chapter on TweakUI by Microsoft Press When an application needs your attention—or when it simply wants to annoy you—it steals the focus from the application in which you’re currently working. This leads to frustration as you flip back and forth between windows. The settings in the Focus category prevent that scenario by causing applications to flash their taskbar buttons to get your attention rather than stealing focus from the application in the foreground.

Setting Name Type Data
HKCU\Control Panel\Desktop
Prevent applications from stealing focus ForegroundLockTimeout REG_DWORD N
Flash taskbar button until I click on it ForegroundFlashCount REG_DWORD 0x00
Flash taskbar button N times ForegroundFlashCount REG_DWORD N