Best Practices for Applying Service Packs, Hotfixes and Security Patches

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By Rick Rosato, Technical Account Manager, Microsoft Corporation


This paper recommends a series of best practices for deploying Microsoft service packs, hotfixes and security patches. The information contained in this document has been derived from Microsoft Technical Account Managers, Microsoft Product Support Services (PSS) engineers, and well-known Microsoft subscription products like Microsoft TechNet and Microsoft Developer's Network (MSDN).

On This Page

Generic Best Practices
Service Pack Best Practices
Hotfix Best Practices
Security Patches Best Practices
Appendix A - Definitions


Service packs, hotfixes and security patches are updates to products to resolve a known issue or workaround.

Moreover, service packs update systems to the most current code base. Being on the current code base is important because that's where Microsoft focuses on fixing problems. For example, any work done on Windows 2000 is targeted at the next service pack and hotfixes are built against the existing available base.

Individual hotfixes and security patches on the other hand should be adopted on a case-by-case, "as-needed" basis. The majority of security updates released are for client side (often browser) issues. They may or may not be relevant to a server installation. Evaluate the update, if it's needed, then apply it. If not, assess the risk of applying or not.

For a full description of service packs, hotfixes and Security Updates, please refer to Appendix A ?Definitions.

The basic rules are:

"The risk of implementing the service pack, hotfix and security patch should ALWAYS be LESS than the risk of not implementing it."


"You should never be worse off by implementing a service pack, hotfix and security patch. If you are unsure, then take steps to ensure that there is no doubt when moving them to production systems."

The following guidelines outline the recommended processes to follow before implementing service packs, hotfixes and security patches. You can follow them as a step-by-step guide to having a successful implementation of any Microsoft recommended update.

Generic Best Practices

These apply to all updates regardless of whether they are service packs, hotfixes or security patches. The generic items listed below are mandatory steps that need to be performed across all updates. In addition, there are specific best practices for each type of update, and these are listed under each update.

  • Use a change control process.

    A good change control procedure has an identified owner, a path for customer input, an audit trail for any changes, a clear announcement and review period, testing procedures, and a well-understood back-out plan. Change control will manage the process from start to finish. If your current procedure is lacking any of the above, please reconsider carefully before using it for deployment of updates.

  • Read all related documentation.

    Before applying any service pack, hotfix or security patch, all relevant documentation should be read and peer reviewed. The peer review process is critical as it mitigates the risk of a single person missing critical and relevant points when evaluating the update.

    Reading all associated documentation is the first step in assessing whether:

    • The update is relevant, and will resolve an existing issue.

    • Its adoption won't cause other issues resulting in a compromise of the production system.

    • There are dependencies relating to the update, (i.e. certain features being enabled or disabled for the update to be effective.)

    • Potential issues will arise from the sequencing of the update, as specific instructions may state or recommend a sequence of events or updates to occur before the service pack, hotfix or security patch is applied.

    Documentation released with the updates is usually in the form of web pages, attached Word documents and README.TXT files. These should be printed off and attached to change control procedures as supporting documentation.

    As well as the documentation released with the updates, a search on the Premier Web site ( for Premier customers or a search on the public Microsoft Support site ( needs to be done for any additional post-release information on the update. TechNet also has the "List of Bugs Fixed in <product name> Service Pack <n>" articles. This is a critical document that must be referenced.

  • Apply updates on a needs only basis.

    One of the common misconceptions about Microsoft updates is that they are mandatory and/or urgent.

    All updates, regardless of their type (whether they are service packs, hotfixes or security patches), are to be applied on an "as-needed" basis. They need to be evaluated individually and treated as important optional updates.

    Especially with security patches, the expectation is that it must be an urgent issue and must be deployed quickly. Without trying to detract from the urgency, security patches are very much a relative update; for example, customers using solely Windows NT4 can ignore a patch for a security vulnerability in Windows 2000. However, if the issue is relevant and does plug a security hole, then it should be evaluated urgently.

    Only when it addresses or fixes an issue being experienced by the customer should it be considered. Of course, it still needs to be evaluated before being installed.

  • Testing.

    The prior points really assist in giving you a feel (before installing) for the potential impact, however, testing allows for the "test driving" and eventual signing off of the update.

    Service packs and hotfixes must be tested on a representative non-production environment prior to being deployed to production. This will help to gauge the impact of such changes.

  • Plan to uninstall.

    Where possible, service packs, hotfixes and security patches must be installed such that they can be uninstalled, if required.

    Historically, service packs have allowed for uninstalling, so verify there is enough free hard disk space to create the uninstall folder.

  • Consistency across Domain Controllers.

    Service packs, hotfixes and security patch levels must be consistent on all Domain Controllers (DCs). Inconsistent update levels across DCs can lead to DC-to-DC synchronisation and replication related problems. It is extremely difficult to trap errors caused by DCs being out of sync, so it's critical that consistency is maintained.

    Where it is practical, Member Servers should also be updated with the same service packs and hotfixes as the Domain Controllers.

  • Have a working Backup and schedule production downtime.

    Server outages should be scheduled and a complete set of backup tapes and emergency repair disks should available, in case a restoration is required.

    Make sure that you have a working backup of your system. The only supported method of restoring your server to a previous working installation is from a backup. For more information on backup and recovery procedures, please refer to:

    • " Backup " in the Microsoft Windows 2000 Server Resource Kit Server Operations Guide.

    • " Repair, Recovery, and Restore " in the Microsoft Windows 2000 Server Resource Kit Server Operations Guide.

  • Always have a back-out plan.

    A back-out plan will allow the system and enterprise to return to their original state, prior to the failed implementation. It is important that these procedures are clear, and that contingency management has tested them, because in the worst case a faulty implementation can make it necessary to activate contingency options.

    Enterprises may need to exercise their back-out plan in the event of the update not having an uninstall process or the uninstall process failing. The back-out plan can be as simple as restoring from tape, or may involve many lengthy manual procedures.

  • Forewarn helpdesk and key user groups.

    You need to notify helpdesk staff and support agencies (such as Microsoft Product Support Service - PSS) of the pending changes so they may be ready for arising issues or outages.

    In order to minimize the user impact, it is also a good idea to prepare key user group of proposed updates, this will assist in managing user expectations.

  • Don't get more than 2 service packs behind.

    Schedule periodic service pack upgrades as part of your operations maintenance and try never to be more than two service packs behind.

  • Target non-critical servers first.

    If all tests in the lab environment are successful, start deploying on non-critical servers first, if possible, and then move to the primary servers once the service pack has been in production for 10-14 days.

Service Pack Best Practices

There are great Microsoft TechNet articles that reference Service Pack Best Practices. All you need to know can be found in the documents list below:

Hotfix Best Practices

  • Service Pack (SP) level consistency.

    Don't deploy a hotfix until you have all current service packs installed. A hotfix is related to a service pack and should be deployed with this in mind. If a hotfix is for post-Windows 2000 SP2, for example, then you need to ensure that the server has SP2 installed.

  • Latest SP instead of multiple hotfixes.

    If multiple hotfixes are to be applied and these are in the latest released service pack, apply the latest service pack instead of applying several hofixes, unless issues relating to the latest service pack may cause the server to break.

Security Patches Best Practices

  • Apply admin patches to install build areas.

    It is crucial that not only clients are retrospectively updated with security patches, but the client built areas are updated for any new clients. Admin patches are required and differ from the client patch. They need to be applied to client build areas. The admin patches are usually located in a different location to the client-side patches. For example, the admin Office Security patches are available from the Office Resource Kit Toolbox at:

  • Apply only on exact match.

    Apply these fixes only if you encounter exactly the issue the fix solves or if the circumstances relate to your environment.

  • Subscribe to email notification.

    Subscribe to the notification alias to receive proactive emails on the latest security patches.


It is critical that when service packs, hotfixes, and security patches are required to be installed, that these best practices be followed. They will guide you through the successful deployment of an update, and will assist your enterprise's recovery should the update fail.

Appendix A - Definitions

Service packs

Service packs correct known problems and provide tools, drivers, and updates that extend product functionality, including enhancements developed after the product released. They get you up to our current code base. Being on the current code base is important because that's where we fix the code.

Service packs keep the product current, and extend and update your computer's functionality. Service packs include updates, system administration tools, drivers, and additional components. All are conveniently bundled for easy downloading.

Service packs are product specific, so there are separate ones for each product. Being product specific does not however, mean that they are SKU (Stock-Keeping Unit) specific. For example, Windows NT 4.0 Server and Workstation will use the same service pack.

Service packs are cumulative - each new service pack contains all the fixes in previous service packs, as well as any new fixes. You do not need to install a previous service pack before you install the latest one. For example, Service Pack 6a contains all the fixes in SPs 1, 2, 3, 4, 5 and 6.

Hotfixes or QFE's

QFE (Quick Fix Engineering) is a group within Microsoft that produces "hotfixes" - code patches for products that are provided to individual customers when they experience critical problems for which no feasible workaround is available.

Hotfixes are not intended for general installation, since they do not undergo extensive beta testing when they are created. Microsoft targets hotfix support toward enterprise-level customers and designs it to provide an extra level of security for mission-critical software systems.

Groups of "hotfixes" are periodically incorporated into service packs that undergo more rigorous testing and are then made generally available to other customers.

They are not regression tested. Hotfixes are very specific - you should apply one only if you experience the exact problem they address and are using the current software version with the latest service pack.

General criteria to meet in order for an issue to be evaluated for a potential bug fix are:

  • Excessive loss of work or revenue to the customer

  • No reasonable, Customer accepted, workaround exists

  • Priority given to Premier accounts

Microsoft offers full n-1 QFE support. This means that we will support the current shipping version of a product and its predecessor. "Version" is defined as a new release with some added functionality and does not include "A" level releases, which are considered strictly maintenance releases. For example, if version 3.5 is superseded by version 3.5A, bug fixes will not be done on 3.5 since 3.5A is a maintenance release. On the other hand, if version 4.21 is superseded by version 6.0 (a functionality release), bug fixes will continue to be done against 4.21 until another version ships. If there is not an update to a product, (ex: LAN Manager) then we will continue to do bug fixes until such point when volume has significantly slowed. We will apprise our Customers at least 6 months in advance of us discontinuing QFE support**.**

Security Patches

Security patches eliminate security vulnerabilities. Attackers wanting break into systems can exploit these vulnerabilities. These are analogous to hotfixes but are deemed mandatory if the circumstances match and need to be deployed quickly.

The majority of security updates released are for client side (often browser) issues. They may or may not be relevant to a server installation. You need to obtain both the admin patch and the client patch as the client patch will retroactively update your client base and the admin patch will update your client build area on the server.

Great articles on security patches are available at:

As mentioned above, the admin patches are located in a different location to the client-side patches. For example, the admin Office Security patches are available from the Office Resource Kit Toolbox at

You also need to be aware that Microsoft makes available four primary areas to obtain client software security patches for its products. This means that if users have access to the Internet, they may have updated their PCs using one of the four mechanisms.

  • Windows Update It uses ActiveX technology to scan the PC to see what has been installed and presents a list of suggested components that need upgrading based on the most up-to-date and accurate versions.

  • Recent security bulletins can be found at This is the best place to search for purely security-related patches, especially since it was upgraded to allow searching by product or date.

  • You can also visit product-specific security patch download pages. They are available for Internet Explorer (IE) and Office Updates. The IE download page is a simple, chronological list of security patches that makes it easy to click down the list and get what you need. Unlike WU, however, there is no facility for identifying which patches have already been installed.

  • Finally, search the Microsoft Download Center (MDC) for security-related patches using the keyword "security_patch." MDC allows searches by product name, product category, or operating system. Unfortunately, you cannot search by both keyword and these other categories simultaneously, so it is not as effective a search mechanism as the security bulletins page. Use this one if you are only browsing, or if the other methods above failed to produce adequate results.