Cleaning up Windows 7/Server 2008 R2 Service Pack data.
Installing a Service Pack on Windows is generally a good idea, but there is one disadvantage to it; it takes up additional disk space. In part, this is because the system keeps additional data in place on the machine, in case you want to uninistall the Service Pack again.
In most cases, you would never want to uninstall a Service Pack, so removing this additional data could reclaim precious disk space. To do this, execute the following command in an admin command prompt:
dism /online /cleanup-image /spsuperseded /hidesp
After the process has finished, you should have reclaimed around 1-2 GB of disk space.