Windows Vista has greatly enhanced its search algorithm where the search process is now not only faster, but users can also easily search for almost all kind of files, documents, pictures, videos, emails and contacts in Outlook 2007, and even commands or application programs’ executables. To achieve the fast searching speed, indexing service plays a pivotal role. Windows Vista starts to crawl and index files on hard disks right after installed with a low priority background process. If you notice that your hard drive activity LED light is constantly flashing even if computer is idle, this is probably due to indexer at work.
This is supposedly the case - indexing at system idle period in order to minimize the performance penalty affected on normal usage. However, this may not be the case in Vista, as the search indexing related processes such as SearchProtocolHost, SearchFilterHost and SearchIndexer actively running even though computer is processing other more critical tasks or running important applications, effectively slow down overall computer performance by sucking up important CPU, memory and other system resources.
So to speed up Vista, users may want to turn off and disable the search indexer and indexing service. You can and should also disable the indexing of files if you’re using other desktop search utility such as Google Desktop Search and etc. If you don’t mind the slower searching speed when performing searches, the indexing has no meaningful use to you too. There are several ways to do this, as listed at the guide below.
Microsoft, Windows Vista, Search, Indexing, Tips and Tricks, Knowledgebase