This update resolves issues associated with the catalog database Windows uses to ensure the integrity of installed binaries. Update 817287 allows the database to repair itself if corruption occurs. This update also improves performance of the catalog database & anything using Microsoft Cryptographic Services NT Service (CryptSvc.dll), including Microsoft Windows Media Player, & Microsoft Media. After you install this item, you may have to restart your computer. Once you have installed this item, it cannot be removed.