Why !xSpeed.net "speed up computer" mode is useless?
You should update the computer driver, Use Standard PC or Advanced Configuration and Power Interface (ACPI) PC.
Open Control Panel ->Performance and Maintenance->System->Hardware->Device Manager->Computer->run the Hardware Update Wizard and Select "Don't search, I will choose the driver to install." ->use the Standard PC or Advanced Configuration and Power Interface (ACPI) PC->restart your pc maybe twice.
More detail
How to use "stop or resume speed up" hotkey?
Some online game check speed changed by game server, Press Hotkey F8 twice can speed up shortly, the server can't find speed change.
Why the hotkey is invalid in Vista?
Run the game you want to speed up as administrator.
Why !xSpeed.net show error message "!xSpeed.net driver initialize failed" when open "speed up computer" mode in Vista?
Run !xSpeed.net as administrator.