The '''Windows System Assessment Tool''' ('''WinSAT''') is a module of [[Microsoft]] [[Windows Vista]], [[Windows 7]], [[Windows 8]], [[Windows 8.1]], [[Windows 10]], and [[Windows 11]] that is available in the [[Control Panel (Windows)|Control Panel]] under ''Performance Information and Tools'' (except in [[Windows 8]], [[Windows 8.1]], [[Windows 10]], and [[Windows 11]]). It measures various performance characteristics and capabilities of the hardware it is running on and reports them as a '''Windows Experience Index (WEI)''' score. The WEI includes five subscores: processor, memory, 2D graphics, 3D graphics, and disk; the basescore is equal to the lowest of the subscores and is not an average of the subscores.<ref name="Softpedia">{{cite web |title=Windows 7 WEI Scores 6.0 through 7.9 Explained|date=December 13, 2010 |url=http://news.softpedia.com/news/Windows-7-WEI-Scores-6-0-through-7-9-Explained-172277.shtml |publisher=Softpedia |access-date=June 3, 2011}}</ref><ref name="Microsoft_Perfect_Score">{{cite web |title=Earning the top Windows Experience Index score |url=http://windows.microsoft.com/en-gb/windows7/achieving-a-perfect-windows-experience-index-score-in-windows-7 |publisher=Microsoft |access-date=June 3, 2011}}</ref> WinSAT reports WEI scores on a scale from 1.0 to 5.9 for Windows Vista,<ref>[http://windowsvistablog.com/blogs/windowsvista/archive/2006/09/22/windows-experience-index-an-in-depth-look.aspx Vista Team Blog : Windows Experience Index: An In-Depth Look]</ref> 7.9 for Windows 7,<ref>{{cite web| url = http://www.pcworld.com/article/239713/how_to_max_out_your_windows_performance_for_1000.html |title = How to Max Out Your Windows Performance for $1000 | author = Marco Chiappetta |publisher = [[PC World]] | date = September 8, 2011 | access-date=May 17, 2014}}</ref> and 9.9 for Windows 8, Windows 8.1, Windows 10, and Windows 11.<ref>{{cite web | url = http://msdn.microsoft.com/en-us/library/windows/hardware/hh825488.aspx |title = WinSAT Comprehensive | date = October 20, 2013 | publisher = MSDN | access-date=May 17, 2014}}</ref>
The WEI enables users to match their computer hardware performance with the performance requirements of software. For example, the [[Windows Aero|Aero]] [[graphical user interface]] will not automatically be enabled unless the system has a WEI score of 3 or higher.<ref>{{cite web |title=Full screen previews have got disabled. How do I re-enable them? |url=http://answers.microsoft.com/en-us/windows/forum/windows_7-desktop/full-screen-previews-have-got-disabled-how-do-i-re/d44193c0-7e51-4a2f-8ec0-4ac115c710c0 |publisher=Microsoft |access-date=June 3, 2011}}</ref><ref>{{cite web |title=What Is the Windows Experience Index |url=http://windows.microsoft.com/en-US/windows-vista/What-is-the-Windows-Experience-Index |publisher=Microsoft |access-date=June 3, 2011}}</ref>
