Consider the following scenario. You enable the hybrid sleep feature on a Windows Vista-based computer. The computer has PS/2 devices that are connected. The computer experiences a power loss. In this scenario, the PS/2 devices may not function when the computer resumes power.

After you upgrade a computer to Windows Vista, keyboard input may be displayed very slowly. For example, you may type many characters before any characters are displayed on the computer screen. Additionally, CPU usage may spike when you use the keyboard. This behavior may momentarily freeze the system.

This problem occurs when you use a PS/2 keyboard or a wireless keyboard that uses a PS/2 adapter.

Note: This problem does not occur if you use a USB keyboard.