I can't connecting WD external drive into laptop using firewire

I would not think this should be necessary, but...

If you see your "networking" icon in your system tray, double-click on it...
Otherwise, go to "Start" -> "Control Panel" -> "Network Connections"
Either of these will bring up a window where you can see if your 1394 connection is

• "enabled"
• "disabled" or
• "connected"

See if you can enable your 1394 from this window.

If not, then right click on "my computer", Then click "properties" (last selection in the menu)
Then click the "hardware" tab and then the "device manager" button
click the "view" drop down menu, and check/tick the option "show hidden devices".

If you find any items in the device manager with yellow or red icons, this may be where your problem lies.

Try updating or rolling back the driver for your 1394 adapter
which should be found under "Network Adapters".

Another possibility may be if your computer already had a 1394 adapter, and your add-on is conflicting.
Again, this should be revealed by device manager.

HTH