I have seen this problem on two different PCs and the fix was the same for both (one case two PCs networked and other case PC connected to ADSL modem via ethernet cable). One PC has XP Home SP2 and other has XP Pro SP2.
In both cases the network stopped working. Installed a new NIC card and tried network on card but would not work. Changed ethernet cable back to onboard lan and network works fine (NIC card still installed).
Does anyone know what would cause the network to suddenly stop and why having a NIC installed but not used, fixes the problem.
