Recently my vista display a red cross on the network indicator and I can’t recall what I’ve done or install. Weird thing is my network connection is working fine without any
interruption but the network icon just displaying red cross there is sometimes quite difficult to know if the network is working fine or not.
So I search the Google for any solution to fix it but failed to find any but on the found 1 from Microsoft and it does not provide any solution just ask to ignore the red cross on the network, here is the write-up from Microsoft
To work around this problem, you can safely ignore the red "X" over the connection icon that indicates that the network adapter is disconnected. The connection status is updated correctly even when the connection icon incorrectly displays a red "X."
What a good answer from Microsoft and i think they not going to fix it as Windows 7 is coming…think so. Here is the full article of the write-up.