Turn this:

        <FilePath>
          <FileName>\Symantec AntiVirus\Rtvscan.exe</FileName>
          <Location>
            <Registry>
              <Key>HKEY_LOCAL_MACHINE</Key>
              <SubKey>SOFTWARE\Symantec\InstalledApps</SubKey>
              <Value>SCS Install Directory</Value>
            </Registry>
          </Location>
        </FilePath>

Into:

        <FilePath>
          <FileName>Rtvscan.exe</FileName>
          <Location>
            <Directory></Directory>
          </Location>
        </FilePath>