No, it's worse:
The XP PC has no trouble accessing the LAN, or Internet.
The Windows 7 PC refuses to talk to anything except the router about 70% of the time. The rest of the time it sort of works. ie Like Vista it sometimes takes 30 minutes, or more, to respond to a simple request. Programs that work most of the time just die for no apparent reason.
I'm used to LAN errors screwing up Word documents, but screwing up the operating system is a real pain.
What really annoys me is that the Reliability Monitor blames applications (Windows Explorer is the program that hangs most often), or the User (I have to force the PC to switch off, if I want to use it). Have you heard the phrase "Teflon shoulders"? It means that criticism just slides off.
Microsoft have a Teflon corporation.
I suspect that there is also a problem with USB hard drives too, but haven't gathered enough evidence - been too busy trying to work out what's wrong with the LAN