A reliability and performance update is available for computers that are running Windows Vista SP1 and Windows Server 2008

Update information

An update is available that will help improve the performance and reliability of Windows Vista Service Pack 1 (SP1) and of Windows Server 2008. If you are not sure whether you have Windows Vista SP1 installed, see the "How do I find out whether I have Windows Vista SP1 installed?" section.

To install the correct version of this update, you must know whether your Windows Vista SP1-based or Windows Server 2008-based platform type is 32-bit or 64-bit. If you are not sure which platform type is installed, see the "How do I find out whether I'm running a 32-bit or 64-bit version of Windows Vista or Windows Server 2008?" section.

If you do have Windows Vista SP1 or Windows Server 2008 installed, and you know whether your platform is 32-bit or 64-bit, you can download the update by clicking one of the following links.

Windows Vista, 32-bit versions

Download the Update for Windows Vista (KB955302) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=F052B9A2-59BE-49CF-BFAE-2F1B2A2A18CB)

Windows Vista, 64-bit versions

Download the Update for Windows Vista for x64-based Systems (KB955302) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=FAC68CEE-CA08-4A0E-A50B-F6F6C4D6B437)

Windows Server 2008, 32-bit versions

Download the Update for Windows Server 2008 (KB955302) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=0026948C-6F39-4B76-9CF0-394EDCE6DE15)

Windows Server 2008, 64-bit versions

Download the Update for Windows Server 2008 x64 Edition (KB955302) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=170386EE-C2E7-49D5-8572-1BA05718EFF0)

Windows Server 2008, Itanium-based versions

Download the Update for Windows Server 2008 for Itanium-based Systems (KB955302) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=E1764790-29EB-47B5-BBCA-D827675F5815)

How do I find out whether I have Windows Vista SP1 installed?

1. Click Start, right-click Computer, and then click Properties.
2. A window is displayed where you can view basic information about your computer. If you have Windows Vista SP1 installed, you see a reference to Service Pack 1 under the Windows edition section.

How do I find out whether I'm running a 32-bit or 64-bit version of Windows Vista or of Windows Server 2008?

1. Click Start, right-click Computer, and then click Properties.
2. A window is displayed where you can view basic information about your computer. In the System type information under the System section, you can see whether a 32-bit or 64-bit version of Windows Vista or of Windows Server 2008 is listed.

Information for advanced users and IT professionals

This update resolves issues that may affect some Windows Vista SP1-based or Windows Server 2008-based computers. These issues have been reported by customers who use the Error Reporting service or Microsoft Customer Support Services.

This update improves the performance, stability, and reliability of Windows Vista SP1 and of Windows Server 2008 in various scenarios. These improvements includes the following:

• Improvements to the stability of Windows Vista SP1-based or Windows Server 2008-based computers that use Windows ReadyBoost technology.
• Improvements to the performance of wireless adapters when you switch between preferred networks after the computer resumes from hibernation.
• New functionality to prevent a data loss scenario when certain registry keys are missing while the Microsoft Disk Cleanup tool is running.
• Improvements to system reliability when Group Policy settings and SMB signing are used.
• Improves the stability of systems that are performing intense graphics processing.

Prerequisites

To apply this update on a Windows Vista-based computer, you must have Windows Vista Service Pack 1 (SP1) installed.

For more information about Windows Vista Service Pack 1, click the following article number to view the article in the Microsoft Knowledge Base: There are no prerequisites to apply this update on a Windows Server 2008-based computer.

Restart information

You must restart the computer after you apply this update.

Hotfix replacement information

This update does not replace any Windows Vista SP1 or Windows Server 2008 updates or hotfixes.

File information

The English version of this update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.Download information

Windows Vista, 32-bit versions

Windows Vista, 64-bit versions

Windows Server 2008, 32-bit versions

Windows Server 2008, 64-bit versions

Windows Server 2008, Itanium-based version

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.