The Win32.clspring is also called "Adware.PurityScan" by Norton. Norton provides a link to the website that created it so you can uninstall it.
http://www.symantec.com/security_response/writeup.jsp?docid=2003-090516-2325-99&tabid=1
I have Zone Alarm antivirus, and I had this same spyware, and after I used the PurityScan's website uninstaller, my Zone Alarm came back saying that it had been successfully "treated." All of my spyware/antivirus scans are coming back clean now, even after several reboots (This infection used to show itself, then hide, then show itself again after every reboot.). Hope this works for you.
Erica, December 2006