Uncompress per this link: click here
The Windows disk management console often baulks at touching the boot partition so a third party tool such as Acronis Partition Manager would be needed but be aware that there is always an element of risk.
My preferred solution is to move 'My Documents' to another partition - just right click and select the new location. Also move your mail file - usually from with the mail client.
It is also possible to set up a second 'My Programs' directory in a second partition and install less important programs there.