Hi -
1. The default Ubuntu drivers should work fine.
But Intel also has up-to-date Linux drivers on their web site:
http://www.intel.com/support/motherb.../CS-030044.htm
<= RTL8169 driver should be fine for your RTL8111d on-board NIC/Intel DG41TY mobo
2. Since you've apparently got a multi-boot system, and since the NIC apparently works in Windows, it's probably NOT a h/w problem (good!)
3. Please try the following:
a) DELETE your network interface
b) Reboot Ubuntu
c) Try auto-detect/auto-configure
4. If that doesn't work, please:
a) Run "lspci", see if it detects the device
b) Run "dmesg", see if there were any errors/warnings at startup
c) Look at /var/log/messages syslog, see if there are any errors/warnings
d) Run "insmod", see if the correct RTL driver is loaded
Please post back what you find!
Your .. PSM
PS:
My experience is that the new GUI "NetworkManager" doesn't always play nice with old-school "ifconfig" style manual configuration. Focus on one or the other (cmd-line or GUI), but don't try to mix'n'match.
Frankly, I'd encourage you to use the GUI exclusively - at least until your network configuration is stabile again.
PPS:
If you've ALREADY got your network working, then please mark your thread "SOLVED".
As to *why* the problem occurred - all I can say is "Sometimes, ca-ca happens
"