Partition Drive Space

We are currently running windows 2003 server. We are running out of space on the C drive on it. Will it cause a problem with the server to move to uninstall files from the windows updates to help free some space. If you have any ideas about repartioning the system drive, let me know. It is currently set up with a C (4 gigs) and E drive (120 gig). Is there anyway to repartion them without loosing the data stored on them?