Windows 7: WIN7 & XP network access

Excellent point...Now you have me wondering if perhaps the installation of Windows 7 and it's subsequent driver installation for your network adapter may have either added some features that weren't present before, (like the infamous task offload issues) or perhaps and maybe even more likely is causing problems with auto negotiation, maybe you can try setting the Win 7 end to 100 full or 100 half, or maybe match them up on both ends. Just another thought.

Thanks zzz
I applied your settings as instructed , leaving default gateway and DNS empty (hope that was OK).
I pinged but it timed out. ???

The drivers for the Windows 7 computer were downloaded and updated from the Realtek site Windows 7 64 bit drivers, they indicate they are working fine.
Pat I don't know about 100 full or 100 half (googled but no joy) can you give me a walk through.

Leave it empty, you need to fill "Default Gateway" ONLY IF you need to access an external network (example: internet). Disable BOTH Windows XP and Windows 7's Firewall. Re-ping.

100Mbps Full Duplex/Half Duplex only states that you can have 100Mbps up AND down (Full Duplex), or 100Mbps up OR down (half duplex).

The difference is, you can only transfer OR receive (half duplex), you can transfer AND receive (full duplex). It's an Old network terminology...

zzz2496

zzz,
I had turned off all firewalls in both computers in the failed ping above. Thank you for the actionable suggestions though. I know this is just a tick the box solution, its just tricky finding that box.

Disable other network interface, re-ping. If it still not ping/ponging... I suggest you look/use another network interface (IIRC you have more than one network interface). Some hardware just doesn't want to work with Windows 7 for whatever reason (I have an old realtek LAN card, in XP it runs fine, in Windows 7... it just broke for no apparent reason, probably the driver).

Before you test using another Network interface, make sure you write down the configuration before applying mine.

zzz2496

I have used the Windows 7 computers same Ethernet LAN port for an Internet connection, directly connected to the modem and had perfect internet connection, this was for up dates and through a firewall. I feel the Ethernet driver is working and its a mother board only 1 year old: GIGABYTE EP45-DS3.

Spuddy, just do whatever you can to make both can ping each other (windows 7 can ping windows xp, and windows xp can ping windows 7). If the network interface are OK on both computers, change the cable. All I need for you now is so that both of your computer can ping each other.

zzz2496

Spuddy, here are some guides that you can use to check if your cable is a cross or straight:

ethernet crossover cable diagram and functionality
How to Make Your Own Network Cables - Network Cable Color Code Standards

Check your cable, make sure it's cross. If your cable is cross, and is operational normally, your computer should be able to ping each other just like that (provided that you followed my IP addressing guide, and both windows only uses the active network connection, that's why I need you to disable other network connection, just in case.). Once your computer can ping each other, all you need to do is put a password on both computer's account, and \\[ip_address]

Hope that helps

zzz2496