The first thing I would do is run a full scan in safemode with the latest definitions installed..
Boot into safe mode and run a Disk Cleanup (right-click the C drive, Properties, Disk Cleanup) - that will delete all the files that are in these temporary locations, as well as IE's temporary files, etc. Perform a full system scan in safe mode.
If that fails to detect and remove the threats, try running the Norton Power Eraser Tool.
http://security.symantec.com/nbrt/npe.asp?lcid=1033&origin=default
Because the Norton Power Eraser uses aggressive methods to detect these threats, there is a risk that it can select some legitimate programs for removal. You should use this tool very carefully, and only after you have exhausted other options.
Another option is the Microsoft Malicious Software Removal Tool - http://www.microsoft.com/security/pc-security/malware-removal.aspx
In the furture, you can visit the Norton Community for Norton product issues.
http://community.norton.com/norton/
Let me know if this was helpful for you.
Best,
Thomas