Windows 7
Upgraded From Windows XP to Windows 7 Home Premium right at release. Powertoys is gone, but i absolutely need this:
1. Activate “Focus Follows Mouse”
Go to: [HKEY_CURRENT_USER\Control Panel\Desktop] For full X-Mouse, add +41h to the first number stored in binary key "UserPreferencesMask". If you only want "focus follows mouse," add +1h.For example, the value for my key was “9E 3E 07 80 12 00 00 00” I edited it to “9F 3E 07 80 12 00 00 00” to get “focus follows mouse” If I had wanted full X-Mouse, I'’d have edited it to “D9 3E 07 80 12 00 00 00”
After that is done, edit the 32bit dword key “ActiveWndTrkTimeout” to the number of milliseconds (in decimal) that you want it to wait before it changes the focus. If this key does not exist, you can create one. With the key set to zero or no key at all, it will automatically change the focus as soon as your cursor touches a new window.