I have had my build of SP1 Windows 7 Service Pack 1 Build 7601.17514.101119-1850 for a Month now since it was first leaked, For a short while Softpedia had this same exact build on there site. If you want to remove all the back up files to free disc space SP1Creates, here are the instructions. However remember if you remove all the backup files you cannot uninstall SP! The following are the instructions
How to cleanup old hot fix information after installing SP1 (cleanup tool)
Once Service Pack 1 is installed you may opt to remove old information regarding old hot fixes and the SP1 un-installation tool as well. Note that if you perform this step you can NEVER remove SP1! It may behoove you to keep a full image pre SP1 backup of your system if you ever want to go back
On most systems you should expect between 500MB and 1.5GB of space recovered by running this program. To run you must launch a command prompt with Administrator privileges, then execute the following command:
dism /online /cleanup-image /spsuperseded