Iburnell,
Even without the exact location for the MSI file on the old location, you can still remove the software.
Problem is, you are using 10.1.4400 where most documentation will point you in the direction of removing 11 nowadays.
Open Registry Editor
******
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
******
Find the product code for Symantec 10.1.4400
Msiexec /q /x {Product key as found in the registry} (from RUN or command prompt)
Should get that right out of there for you...