you can use the cleanwipe if you have or use the manual uninstall process

http://www.symantec.com/business/support/index?page=content&id=TECH161956

Hello,

What version of SEP 12 (SEP 12.0 or SEP 12.1), did you use??

I would request you go with manual Uninstallation Steps (as pete suggested above) OR log a case on web portal to receive CleanWipe version 12.1 Utility.

Hope that helps!!

Check wether Teefer2 Driver is installed or not.

Remove the Teefer driver (may not be present):

1. Click Start > Run.
2. Type regedit, and click OK.
3. Navigate to the following key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network\{4D36E974-E325-11CE-BFC1-08002BE10318}
4. Find the keys that have a value of ComponentId that is set to symc_teefer2, and update the value of Characteristics to 40000.
5. Navigate to the following key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network
6. Delete the value Config.
7. Exit the Windows Registry Editor.
8. Click Start > Settings > Control Panel > Network Connections.
9. Click a connection.
10.  In the dialog, click Properties.
11. Select Teefer Driver, and click Uninstall.
12. Repeat these steps for each Network Connection.
13. Restart the computer.