This release of Windows NT® 4.0 Service Pack 6a is easy to download while Windows NT 4. is running. Windows NT 4.0 Service Pack releases are cumulative, so this release contains all previous Service Pack updates, as well as new updates created after Service Pack 5. This is not a required upgrade. Microsoft provides software and updates to resolve critical issues in earlier service packs.

Service Pack 6a (SP6a) resolves the SP6 issue with Lotus Notes, and other Winsock-based applications, and provides the latest updates to Microsoft Windows NT Workstation 4.0 and Windows NT Server 4.0 (including Enterprise Edition). SP6a contains known Year 2000 updates for Windows NT 4.0. These Year 2000 updates are also available as separate Web downloads that customers may apply to a Service Pack 4 system. Providing these options gives organizations the flexibility to choose which path is easier for them to address Year 2000 issues. SP6a is not a required upgrade for Year 2000; Microsoft recommends that each customer consult the SP6a documentation and then determine whether to deploy it.

SP6a includes the following updates to SP6:

• The update for the SP6 issue with Lotus Notes and other Winsock based applications. This issue prevents connecting to the server when the current user is not logged in with administrator rights. For more information about this issue please read Microsoft Knowledge Base Article Q245678. (This site is in English.)
• In accordance with Microsoft's commitment to Year 2000 compliance, SP6a includes an update to the IIS 3.0 log converter utility, convlog. For more information about this, please read Microsoft Knowledge Base Article Q245329. (This site is in English.)
• Winver.exe has been revised to allow the user to quickly verify whether a system is running SP6a.

Important To avoid problems, including possible data loss, if you use both Microsoft Outlook and Computer Associates Inoculan, you should verify that you are using the latest version of the Inoculan drivers before installing SP6a. To obtain the latest drivers, please visit http://www.support.cai.com. (This site is in English.) Other applications and prior versions of Service Packs may be affected as well. For additional details, please read Microsoft Knowledge Base Article Q244652. (This site is in English.)

Important Microsoft recommends that you stop running any critical services before you apply Windows NT 4.0 SP6a.

For more installation recommendations and additional information about the new service pack, read Windows NT 4.0 Service Pack 6a. (This site is in English.)

• 60 MB storage space for both X86 and Alpha. (If you wish to have an uninstall directory, the storage space requirement increases to 120 MB for both X86 and Alpha.)
• No Service Pack requirements needed.
• Windows NT Workstation 4.0, Windows NT Server 4.0 or Windows NT Server 4.0, Enterprise Edition installed.

If you created an unininstall archive at the time of installation, Windows NT 4.0 Service Pack 6a can be partially uninstalled. To uninstall Service Pack 6a:

1. Click the Start button, point to Settings, and then click Control Panel.
2. Double-click Add/Remove Programs.
3. Click Windows NT 4.0 Service Pack 6a.
4. Click Add/Remove.

Note These procedures do not completely remove all SP6a changes from your system. Windows NT 4.0 Service Pack 6a can be partially uninstalled if you create an uninstall archive.