Have you tried this?

 Code:
IF $VISTA32="YES" OR $VISTA64="YES"
 $NETWORKKEY='$HKLM\$SMWCV\Policies\System'
	
 IF Not KeyExist($NETWORKKEY)
  $=AddKey($NETWORKKEY)
  $=WriteValue $NETWORKKEY,"EnableLinkedConnections","00000001",REG_DWORD)
 ELSE
  $=WriteValue($NETWORKKEY,"EnableLinkedConnections","00000001",REG_DWORD)
 ENDIF
ENDIF