3com 3c920 network card

[Duc Dung]

I am using Toshiba Tecra 8200 with docking base
- 3Com 3C920 Integrated Fast
Ethernet Controller (3C905C-TX Compatible) network card.
I have problem about Network when I upgraded from Windows
2000 profession to Windows XP profession.
1- All thing is OK
2- But I open a file on Local network very low. Why ?
(If open this file on hard disk very quick, local network
is good)

Please help me ASAP
Best regards,