| Windows Server 2008 R2 | |
|---|---|
| Version of theWindows NT operating system | |
 | |
 Screenshot of Windows Server 2008 R2 showing the Server Manager application which is automatically opened when an administrator logs on | |
| Developer | Microsoft |
| OS family | Windows Server |
| Source model | |
| Released to manufacturing | July 22, 2009; 16 years ago (2009-07-22) |
| General availability | October 22, 2009; 16 years ago (2009-10-22)[1] |
| Latest release | Service Pack 1 with January 2026 monthly update rollup (6.1.7601.28117) / January 13, 2026; 35 days ago (2026-01-13)[2] |
| Marketing target | Business |
| Update method | Windows Update,Windows Server Update Services,SCCM |
| Supported platforms | x86-64,Itanium |
| Kernel type | Hybrid (Windows NT kernel) |
| Default user interface | Windows shell (Graphical) |
| License | Commercialproprietary software (Retail,volume licensing,Microsoft Software Assurance) |
| Preceded by | Windows Server 2008 (2008) |
| Succeeded by | Windows Server 2012 (2012) |
| Official website | Windows Server 2008 R2 (archived atWayback Machine) |
| Support status | |
| Mainstream support ended on January 13, 2015[3] Extended support ended January 14, 2020[3] Paid updates; only for Standard, Enterprise, and Datacenter volume licensed editions:[4][5] ESU (Extended Security Updates) support ended on January 10, 2023, for non-Azure & January 9, 2024, for Azure.[6][3] Grandfathered[7] Premium Assurance security update support ended on January 13, 2026.[8][9] See§ Paid extended updates for details. | |
| Part ofa series of articles on |
| Windows 7 |
|---|
| Siblings |
Windows Server 2008 R2, codenamed "Windows Server 7" is the eighth major version of theWindows NToperating system produced byMicrosoft to be released under theWindows Server brand name. It wasreleased to manufacturing on July 22, 2009,[10] and becamegenerally available on October 22, 2009, the same respective release dates ofWindows 7.[11] It is the successor to theWindows Vista-basedWindows Server 2008, released the previous year, and was succeeded by theWindows 8-basedWindows Server 2012.
Enhancements in Windows Server 2008 R2 include new functionality forActive Directory, newvirtualization and management features, version 7.5 of theInternet Information Servicesweb server and support for up to 256[12] logical processors. It is built on the samekernel used with the client-orientedWindows 7, and is the firstserver operating system released by Microsoft which dropped support for 32-bit processors, an addition which carried over to the consumer-orientedWindows 11.
It is the final version of Windows Server that includes Enterprise and Web Server editions, the final that got a service pack from Microsoft and the final version that supportsIA-64 and processors withoutPAE,SSE2 andNX (although a 2018 update dropped support for non-SSE2 processors).
Seven editions of Windows Server 2008 R2 were released: Foundation, Standard, Enterprise, Datacenter, Web,HPC Server andItanium, as well as Windows Storage Server 2008 R2. Ahome server variant calledWindows Home Server 2011 was also released.
Microsoft introduced Windows Server 2008 R2 at the 2008Professional Developers Conference as the server variant ofWindows 7, based on theWindows NT kernel.
On January 7, 2009, abeta release of Windows Server 2008 R2 was made available to subscribers of Microsoft'sTechNet andMSDN programs, as well as those participating in the Microsoft Connect program for Windows 7. Two days later, the beta was released to the public via the Microsoft Download Center.[13]
On April 30, 2009, therelease candidate was made available to subscribers of TechNet and MSDN.[14] On May 5, 2009, the release candidate was made available to the public via the Microsoft download center.[15]
According toWindows Server Blog,[16] the following are the dates of the year 2009 when Microsoft Windows Server 2008 R2 has been made available to various distribution channels:
Additionally, qualifying students have been able to download Windows Server 2008 R2 Standard edition in 15 languages from theMicrosoft Imagine program (known as DreamSpark at the time).[17]
A reviewer guide published by the company describes several areas of improvement in R2.[18] These include new virtualization capabilities (Live Migration,Cluster Shared Volumes usingFailover Clustering andHyper-V), reduced power consumption, a new set of management tools and newActive Directory capabilities such as a "recycle bin" for deleted objects. IIS 7.5 has been added to this release which also includes updatedFTP server services. Security enhancements include encrypted clientless authenticated VPN services throughDirectAccess for clients using Windows 7, and the addition ofDNSSEC support forDNS Server Service. Even though DNSSEC as such is supported, only one signature algorithm is available:[19] #5/RSA/SHA-1. Since many zones use a different algorithm – including theroot zone – this means that in reality Windows still can't serve as a recursive resolver.
TheDHCP server supports a large number of enhancements[20] such asMAC address-based control filtering, converting active leases into reservations orlink layer based filters, DHCppPName protection for non-Windows machines to prevent name squatting, better performance through aggressive lease database caching, DHCP activity logging, auto-population of certain network interface fields, a wizard for split-scope configuration,DHCP Server role migration using WSMT, support for DHCPv6 Option 15 (User Class) and Option 32 (Information Refresh Time). The DHCP server runs in the context of theNetwork Service account which has fewer privileges to reduce potential damage if compromised.
Windows Server 2008 R2 supports up to 64 physical processors[21] or up to 256 logical processors per system. (Only the Datacenter and Itanium editions can take advantage of the capability of 64 physical processors. Enterprise, the next-highest edition after those two, can only use 8.)[22] When deployed in a file server role, new File Classification Infrastructure services allow files to be stored on designated servers in the enterprise based on business naming conventions, relevance to business processes and overall corporate policies.[23]
Server Core includes a subset of the.NET Framework, so that some applications (includingASP.NET web sites andWindows PowerShell 2.0) can be used.
Performance improvement was a major area of focus for this release; Microsoft has stated that work was done to decrease boot time, improve the efficiency of I/O operations while using less processing power, and generally improve the speed of storage devices, especiallyiSCSI.
Active Directory has several new features when raising the forest and domain functional levels[24] to Windows Server 2008 R2: Two added features are Authentication Mechanism Assurance and Automatic SPN Management. When raising the forest functional level, the Active Directory recycle bin feature is available and can be enabled using the Active Directory Module for PowerShell.[25]
Support for the RTM version of Windows Server 2008 R2 ended on April 9, 2013.[3][26] Users had to install Service Pack 1 to continue receiving updates.[27]
On January 13, 2015, Windows Server 2008 R2 exited mainstream support and entered the extended support phase; Microsoft continued to provide security updates every month for Windows Server 2008 R2, however, free technical support, warranty claims, and design changes were no longer offered. Extended support ended on January 14, 2020, about ten years after the release of Windows Server 2008 R2.[28]
In August 2019, researchers reported that "all modern versions of Microsoft Windows" may be at risk for "critical" system compromise due to design flaws of hardwaredevice drivers from multiple providers.[29]
Microsoft announced that Server 2008 R2 would be the last version ofWindows supporting theItanium architecture, with extended support to end on July 10, 2018.[30][31][32] However, monthly security updates continued until January 14, 2020,[33] and a final unscheduled update appeared in May 2020 viaWSUS.[34]
Windows Server 2008 R2 was eligible for the paid ESU (Extended Security Updates) program. This program allowed volume license customers to purchase, in yearly installments, security updates for the operating system until January 10, 2023, only for Standard, Enterprise, and Datacenter volume licensed editions. The program was included withMicrosoft Azure purchases, and offered Azure customers an additional year of support, until January 9, 2024.[3][4][6][35]
Prior to the ESU program becoming available, Windows Server 2008 R2 was eligible for the now discontinued, paid Premium Assurance program (an add-on toMicrosoft Software Assurance) available to volume license customers. However, Microsoft honored the program for customers who purchased it between March 2017 and July 2018 (while it was available). The program provided an extra six years of security update support. The Extended Security Updates program for Windows Server 2008 R2 ended on January 13, 2026, marking the final end of all security updates for theWindows NT 6.1 product line after 16 years, 5 months, and 22 days.[9][7][8][36]
Paid extended updates were not available forItanium customers.[37][36]
On February 9, 2011, Microsoft officially released Service Pack 1 (SP1) for Windows 7 and Windows Server 2008 R2 to OEM partners. Apart from bug fixes, it introduces two new major functions, RemoteFX and Dynamic Memory. RemoteFX enables the use of graphics hardware support for 3D graphics in a Hyper-V based VM. Dynamic Memory makes it possible for a VM to only allocate as much physical RAM as is needed temporarily for its execution. On February 16, SP1 became available for MSDN and TechNet subscribers as well as volume licensing customers. As of February 22, SP1 is generally available for download via the Microsoft Download Center and available on Windows Update.[38]
System requirements for Windows Server 2008 R2 are as follows:[39]
| Features | Foundation | Standard | Web | HPC | Enterprise | Datacenter | Itanium |
|---|---|---|---|---|---|---|---|
| MaximumRAM onx86-64 | 8 GB | 32 GB | 256 GB | 2 TB | |||
| Maximum physicalCPUs | 1 | 4 | 8 | 64 | |||
| Failover cluster nodes (Nodes) | N/a | N/a | N/a | N/a | 16 | 8 | |
| Cross-file replication (DFS-R) | No | Yes | Yes | Yes | Yes | Yes | Yes[41] |
| Fault tolerant memory sync | No | No | No | No | Yes | Yes | Yes |
| Memory modules: Hot addition | No | No | No | No | Yes | Yes | Yes |
| Memory modules: Hot replacement | No | No | No | No | No | Yes | Yes |
| CPUs: Hot addition | No | No | No | No | No | Yes | Yes |
| CPUs: Hot replacement | No | No | No | No | No | Yes | Yes |
| IAS connection | 10 | 50 | No | No | Unlimited | Unlimited | 2 |
| Remote Desktop Services connections | 50 | 250 | No | No | Unlimited | Unlimited | No |
| RRAS connections | 50 | 250 | No | 250 | Unlimited | Unlimited | No |
| Virtual image use rights | Forbidden | Host + 1 VM | 1 VM | Host + 1 VM | Host + 4 VMs | Unlimited | Unlimited |
| Features | Foundation | Standard | Web | HPC | Enterprise | Datacenter | Itanium |
Why the change? The natural evolution of the x86 64-bit ("x64") architecture has led to the creation of processors and servers which deliver the scalability and reliability needed for today's "mission-critical" workloads.
SQL Server 2008 R2 and Visual Studio 2010 are also the last versions to support Itanium.
| MS-DOS-based | |||||
|---|---|---|---|---|---|
| Windows NT |
| ||||
| Specialized | |||||
| Windows IoT |
| ||||
| Windows Mobile | |||||
| Windows Phone | |||||
| Cancelled | |||||
| Related | |||||
