Thank you for posting at Wired Communities. Unfortunately there is no Windows 10 driver available for 82566DM as this ethernet controller was launched way back 2006 :
You may refer to our website below for reference that there is no driver for Windows 10
Further, for onboard NIC it is recommended to contact the system or board vendor for the customize driver, you may try checking with Dell* if they have the driver.
Hope the above information help.