If you want to free more your hard drive space,you can do that after removing all the restore points except the most recent use the restore point.
Click Start-> Run. Type: CLEANMGR then hit [Enter] key.
1) Select the hard disk partition and press OK
2) At the top of the dialog, click the tab More Options
3) Under System Restore section, click the button "Clean up..."
Now, all the System Restore points (except the recent one) are cleared and more hard disk space will be free.