Hi guys, I'm in a bit of a pickle. I went into a friends office to help him sort out a couple of slow computers today and I just got a text that his whole network is down. His office is a department in a hotel which has a central network system. And I have no idea how it's set up and no experience past SoHo networking. I initially unplugged a network cable from a desktop and put it into my laptop so I could access the internet. Everything worked fine. However, when I put it back into the desktop, the card only intermittently picked up a signal, though it kept working when I re-plugged it back in to my laptop. Anyway, I figure his problem is his on an old core 2 solo proc with 1gb of ram and go about upgrading that computer. His laptop is ok, but Skype is slow as he's on shared WiFi which is really slow. So, i figure I can hook him up with WiFi through the office by setting up a cheap DD-WRT repeater. I try to hook the cable up to the computer first, no signal, then laptop, no signal, router no signal. So I give up on that and continue upgrading the old core solo (to a E7600). I also try pulling a cable from another socket into the router/repeater, but there's no signal from that either. I tell the girls in the office that they need to contact the IT department to get the network sorted, assuming it's just those 2 connections. (I checked the cables and hardware and all is fine on that end). Before I leave, one other computer is also not connected to the network, one that I didn't touch, but figured that the IT dept can sort that too. I just got a message that all the computers are now not able to connect to the network! I'm wondering if I caused this. Is there any security that would cause a whole office to go down when someone tries to plug in unrecognized/unauthorized devices? Everything I used is virus free and clean, so my computers would not have been trying to attack the network. I figured that the worst that could happen would be that a device is just denied access. Not causing the whole office to go down!