To investigate disk space usage download and install Treesize (freeware).
http://www.jam-software.com/treesize\_free/
Information on Treesize
http://www.jam-software.com/treesize\_free/
When you open Treesize select Scan from the Menu and you will see a list of drives. Click on C and it will generate a list of Folders.
Post the names and the sizes of the 6 largest folders and the total at the top of the list.
A saving easily overlooked. Type Disk CleanUp in the Search Box above the Start Button and press the ENTER key. Click on OK and after the space calculation you will see a window with a list of Files to delete. Use
the scroll bar to the right of the window to see the entries further down the list. Check the box before Service Pack BackUp Files and click on OK
http://www.sevenforums.com/tutorials/122262-windows-7-sp1-disk-cleanup-tool.html
These files need to be retained for perhaps a month after the Service Pack has been installed as they are needed if you need to uninstall the Service Pack. A month is a reasonable time to see whether the service pack
has caused problems.