Windows Vista - http://www.vistaarticles.com
Cannot Shut Down or Power Saving Mode or Sleep or Hibernation or Resume from Sleep or Devices do not work after Sleep or Instability
http://www.vistaarticles.com/articles/251/1/Cannot-Shut-Down-or-Power-Saving-Mode-or-Sleep-or-Hibernation-or-Resume-from-Sleep-or-Devices-do-not-work-after-Sleep-or-Instability
By 
Published on 12/10/2006
 
You may experience one or more of the following power management-related symptoms on a computer that is running Windows Vista.

Power Management Symptoms

Step 1: Update the computer BIOS
Verify that the latest BIOS is installed in the computer. You can use the Msinfo32.exe program to determine the BIOS version. To do this, follow these steps:1. Click Start, type msinfo32 in the Start Search box, and then click msinfo32 in the Programs list.

 If you are prompted for an administrator password or confirmation, type your password, or click Continue. 
2. In the System Information dialog box, click System Summary in the left pane.
3. In the right pane, examine the value that appears next to BIOS Version/Date.
4. Try to locate a BIOS update for the computer. To do this, perform one of the following actions:

Visit the computer manufacturer's support Web site, or contact the computer manufacturer to determine whether a BIOS update is available for the computer.
Visit the computer motherboard manufacturer's support Web site, or contact the manufacturer of the computer motherboard to determine whether a BIOS update is available for the motherboard.
For information about how to contact computer hardware manufacturers, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base:
65416 (http://support.microsoft.com/kb/65416/) Hardware and software vendor contact information, A-K

60781 (http://support.microsoft.com/kb/60781/) Hardware and software vendor contact information, L-P

60782 (http://support.microsoft.com/kb/60782/) Hardware and software vendor contact information, Q-Z
5. If you locate a BIOS update, examine the documentation, or contact the manufacturer to determine whether the update includes changes to resolve the power management problem.

Note Sometimes the documentation may not include information about all the changes that the BIOS update includes. 
6. Use the manufacturer's recommended BIOS update tool to update the computer BIOS.

Step 2: Examine the BIOS settings
Incorrect BIOS settings may cause startup problems or shutdown problems in Windows Vista. Examine the BIOS settings to determine whether the BIOS is configured correctly. For more information about the correct settings for the computer BIOS, contact the computer manufacturer.

Note Although this is not a common scenario, you may experience computer startup issues if you reset the BIOS configuration to its default settings. Therefore, we recommend that you contact the computer manufacturer before you modify the computer BIOS.

Step 3: Troubleshoot third-party power management programs
Examine the computer to determine whether any third-party power management programs are installed. Sometimes, a program that is designed for one particular operating system and BIOS version does not work with other operating systems or BIOS versions. To help troubleshoot this issue, disable or remove power management programs that are not designed for Windows Vista. Visit the program manufacturer's support Web site to help determine whether a particular program is supported for use with Windows Vista.

For information about how to contact computer program manufacturers, click the appropriate article number in the following list to view the article in the Microsoft Knowledge Base:
65416 (http://support.microsoft.com/kb/65416/) Hardware and software vendor contact information, A-K

60781 (http://support.microsoft.com/kb/60781/) Hardware and software vendor contact information, L-P

60782 (http://support.microsoft.com/kb/60782/) Hardware and software vendor contact information, Q-Z