Many a times you might have noticed that when you try to install any windows update or service pack ( I have even seen it happening with driver update in Windows 7 ) it fails for some internal reason or you might also get notice like a restart is pending or a previous installation is not complete. Most of the times these problem go away with rebooting of the system but if not you should try using the Windows System Update readiness Tool.
Windows 7 SP 1 and Windows Server 2008 SP 1 is due next month and we would recommend you to download this tool and make sure your system doesn’t have any issues which fails the update of service packs.
This tool helps to fix this problem which is caused by inconsistency in the Windows servicing store which may prevent the successful installation of future updates, service packs, and software. This tool checks your computer for such inconsistencies and tries to resolve issues if found. download it from here | Thanks Nirmal