Some backstory first- My family has one PC we have been using for storage and for our daughter to play on. It has a 2.5 40gig, 3.5 40gig and 3.5 80gig. The 2.5 40gig finally blew. Luckly this was just an OS drive we had windows 7 on. In fear of the other 2 drives going bad soon, we want to backup our backup to our laptops until we get a good NAS. My laptop had 3 partitions on it, XP, 7 and Ubuntu. I really never use XP or Ubuntu, so I wiped those and resized my win7 partition to fill the whole 250gig drive. After some MBR/BCD headaches all is well. I didn't really want to transfer the 100 gigs of data from the desktop via wireless, so I got a crossover cable to connect it directly to my laptop. I had a older 60 gig that's failing but not dead yet that I threw win7 on in the desktop just so we can transfer the files. While that was setting up, I wanted to verify that things were set up correctly on the laptops. Connected our laptops together, both the exact same inspirion 1525, with exeption that mine is x64 and my wifes is x86 win7. Disabled all firewalls and set up static IPs, they were both already on the same homegroup so I didn't need to mess with that. Connected the x-over cable and nothing happened. My computer would display "identifying" for a split second in network and sharing center then go away again. It did this a few times while I troubleshot windows to verify everything was correct there. Tried disabling/reinabling NIC, turned off wireless, completely uninstalled the NIC and drivers, etc etc etc. By this time i was no longer seeing the network connection pop in and out. Just out of curiosity, since my wife never uses her NIC only wireless, I wired her laptop directly to the router with the proper straight-through ethernet cable. Nothing. Reboot. Nothing. Verify DHCP settings. Nothing. Now win7 is done loading on the desktop, so using the same straight-through network cable, I hook it up and whattaya know it works. So i figure maybe just her NIC was bad. I try my laptop. No good. No lights on the NIC or anything. Do the same uninstall-reinstall procedure on my laptop. Still no good. I had just used this NIC a few days ago. Is it possible that the NICs fried each other? They are both Marvell Yukon 88E8040 PCI-E Fast Ethernet Controllers. Anything else I can try and do? If they are fried, where can I get replacements?
What tutorial were you following to set-up this peer-to-peer network? It is better to read and follow directions instead of a haphazard guessing game.
In general there is not enough voltage on a network card to "blow up" another network card.
I don't have the exact links anymore, but I know one was from Microsoft. They all generally said the same thing, connect the crossover cable, disable firewalls, set up static IPs, and homegroup them together. If it was a software setting issue, I should have at least had an unidentified connection listed for LAN. Just out of curiosity, I used my linux live disk to test and see if it was a windows issue preventing the NIC from functioning, but it didn't work there either, and it was not disabled in the BIOS. The crossover cable tested good, not miswired or shorted.
You're not going to be able to network Ubuntu to Windows 7 with justs a crossover cable without doing some work, so using the Ubuntu Live CD doesn't prove anything.
I would suggest booting both computers in Safe Mode and see if they are able to see each other.