Today Microsoft, released the final version of Windows Search 4.0 to the Microsoft Download Center. Windows Search 4.0 updates search in Windows Vista, Windows XP, Windows Server 2003, Windows Server 2008 and Windows Home Server.
They've introduced some performance and reliability improvements. Queries are faster, as is indexing - how much faster depends on your machine and your data. Improved reliability means that system failures won't get in the way of the indexer and all of your data will be scanned and available for searches.
They've also extended remote index discovery, also known as PC-to-PC searches, which allows data to be searched quickly and efficiently across machines running Windows Search 4.0. This means that Windows Vista-to-Windows XP or Windows Vista-to-Windows Server 2008 queries are now possible.
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