Windows Vista 64-bit editions

Windows Vista 64-bit editions are the 64-bit editions of the Windows Vista family of Microsoft operating systems.Microsoft [http://www.microsoft.com/australia/windows/products/windowsvista/editions/64bit.mspx 64-bit Editions of Windows Vista] ] They differ from the 32-bit editions in that the operating systems operate on the 64-bit mode of processors that support that mode. Those processors include Intel Xeon, Intel Core 2, AMD Opteron and AMD Athlon 64.

All Windows Vista editions are available as either 32-bit or 64-bit editions, except for the Vista Starter edition. [Microsoft [http://www.microsoft.com/windows/products/windowsvista/editions/starter/default.mspx Windows Vista Starter] ] One edition, Vista Ultimate Retail, has both 32-bit and 64-bit editions included. (The OEM version does not include both editions.) [ [http://www.microsoft.com/windows/products/windowsvista/editions/64bit.mspx Windows Vista: 64-bit Editions] ]

An important feature of the Vista 64 editions is their much improved performance over 32 bits versions and they can also significantly outperform the most used 32 bit Windows XP version. [cite web
url=http://blogs.zdnet.com/hardware/?p=1772
title=XP SP3 vs. Vista SP1 - Which is fastest?
author=Adrian Kingsley-Hughes
publisher=ZDnet
date=2008-04-28
accessdate=2008-06-20] [cite web
url=http://64-bit-computers.com/windows-vista-32-bit-vs-64-bit-benchmark.html
title=Windows Vista Benchmark: 64-Bit Faster Than 32-Bit
publisher=64-bit-computers.com
date=2006-12-06] [cite web
url=http://www.exoid.com/?page_id=124
title=Vista 64-Bit Review
date=2007-11-1
publisher=Exoid.com]

Windows Vista 64-bit editions can run the vast majority of 32-bit programs by running them within the WOW64 subsystem, but a few cannot run at all. One example of software that functions differently is Visual Basic 6. The Visual Basic 6 IDE runs natively on Vista 32, but does not run at all on Windows Vista 64. [MSDN [http://msdn.microsoft.com/en-us/vbrun/ms788708.aspx Support Statement for Visual Basic 6.0 on Windows®Vista™and Windows®Server 2008 ™] Microsoft February 2008.] Some applications require separate runtimes for 64-bit and 32-bit.

Old device drivers are particularly problematic, because they need to be rewritten in 64-bit mode. A lot of older hardware doesn't have the necessary support to get the drivers written. [Dan's data - [http://www.dansdata.com/askdan00001.htm Ask Dan: 32 or 64 bit Vista?] February 9, 2007] [CNET [http://news.cnet.com/64-bit-PCs-Drivers-wanted/2100-1003_3-6200517.html 64-bit PCs: Drivers wanted] August 3, 2007] [KezNews [http://keznews.com/3953_6_Caveats_%E2%80%93_64-bit_Windows_Vista 6 Caveats – 64-bit Windows Vista] February 9, 2008]

One important difference between the 64-bit edition and the 32-bit edition is the elimination of the 16-bit subsystem.Supersite for Windows [http://www.winsupersite.com/showcase/winvista_ff_x64.asp Windows Vista Feature Focus: 64-Bit (x64) Support] ] [ [http://support.microsoft.com/kb/946765 A description of the differences between 32-bit versions of Windows Vista and 64-bit versions of Windows Vista ] ] . This is a change from previous versions of 64 bit windows, such as XP-64. Older versions of 64 bit windows used to support some 16 bit programs and installers, but this support has been removed in 64 bit Vista. WOW64 has historically been designed to recognise these installers and to allow their execution, but in Vista this capability has been removed. [cite web
url=http://support.microsoft.com/kb/282423
title=List of limitations in 64-Bit Windows (MSKB282423)
date=October 11 2007
accessdate=2008-06-22
publisher=Microsoft]

While 32-bit editions of Vista technically can address up to 4GB of memory, limitations with the system's hardware allow only 3GB-3.5GB to a 32-bit operating system, allotting any remaining RAM to other system resources. The 64-bit edition greatly expands this limit as the memory pointers can address large address spaces. Microsoft states that some kinds of tasks, working with video and databases, might perform better in a 64-bit environment. [ [http://windowshelp.microsoft.com/Windows/en-US/Help/41531554-d5ef-4f2c-8fb9-149bdc5c8a701033.mspx#EMH Windows Vista Help: 32-bit and 64-bit Windows: frequently asked questions ] ]

The 64-bit editions require all kernel-mode drivers to have a digital signature, [cite web
url=http://www.microsoft.com/whdc/winlogo/drvsign/kmsigning.mspx
title=Digital Signatures for Kernel Modules on Systems Running Windows Vista
date=July 27 2007
accessdate=2008-06-22
publisher=Microsoft] and Kernel Patch Protection was introduced with the 64-bit editions of Windows XP and Windows Server 2003 in 2005 to protect the kernel from being patched while it is running, which aims to improve overall system stability and reduce susceptibility to malware.cite web
url=http://uninformed.org/index.cgi?v=8&a=5&p=2
author=Skywing
title=Introduction
work=PatchGuard Reloaded: A Brief Analysis of PatchGuard Version 3
publisher=Uninformed
month=September
year=2007
accessdate=2007-09-20]

Microsoft has stated that prior to installing the 64-bit operating system, one should be sure that the software you wish to run is capable of running under 64-bits, and that the hardware you wish to use has 64-bit drivers.

External links

* Microsoft [http://windowshelp.microsoft.com/Windows/en-US/Help/41531554-d5ef-4f2c-8fb9-149bdc5c8a701033.mspx 32-bit and 64-bit Windows: frequently asked questions]
* Microsoft [http://support.microsoft.com/kb/946765 Description of differences between 32-bit and 64-bit Vista]

References