If the OS is complaining (new hardware found) about a ethernet controller one of you network conections needs a driver loaded.
You say you have a LNE100TX(v5) add in NIC so you would need to down load those deivers from CISCO \ Linksys site at http://homedownloads.cisco.com/downloads/driver/LNE100TX_v5_drivers.zip
Your board may also have a Intel native NIC addapter built into the mother board ( Intel 82562EZ PLC or Intel 82547EI PLC)
All the board native drivers can be found here http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Desktop+Boards&ProductLine=Intel%c2%ae+865+Chipset+Family+Boards&ProductProduct=Intel%c2%ae+Desktop+Board+D865GLC
or the complete NIC package drivers here http://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&ProdId=923&DwnldID=19233&ProductFamily=Network+Connectivity&ProductLine=Intel%c2%ae+Desktop+Adapters&ProductProduct=Intel%c2%ae+PRO%2f100+VM+Network+Connectioneng
If you check device manager, any thing missing a driver should have a yellow bang by it.