LAN connection to my WD Book

[2quik]

I have my pc connection to my router and my router connected to my network switch. I have a wd my book live due as a back up to my data. ever now and then i try to copy new files to my Wd my book live due. in the past i have been able to connect my WD book to my mother board Lan and copy files, my computer currently has an extra Lan adapter (intel (R) PRO/100 GT desktop Adapter) i use this to connection directly to my router & internet.

Some how when i tired to connect my WD book to my motherboards LAN and the WD book is not recognized, i tired to map a network drive, i click on browse and i can see "MY BOOK" in network but once i click on it i get error "the remote device or resource won't accept the connection". I can connect My Book to my switch and my book is found. I like to connect My Book to my motherboard LAN to transfer files because it's faster but all of the sudden it won't connect any more. I can see both LAN adapters on device manager and there is not yellow exclamation.

Anyone have any ideas on what is going on or how to fix it?
Thanks.

 

[2quik]

yes it seems to be work correctly on LAN1

Would you recommend leaving My Book on Lan1 or connecting to my switch?

 

[GhislainG]

You said that it runs too slow when connected to the switch. If you have a single PC, then keep the current setup.

 

[2quik]

Yes it does when transferring files. I mainly have the WD Mybook as back/storage system.
Thanks for all your help GhislainG. I have learned more about networking.