I am finding my wifi network is a little temperamental due to the upstairs/downstairs location of one PC. The rooms are actually below/above one another against an external wall, so i was thinking of installing a RJ45 wall plate in each room and run a CAT5 cable between them. If i do this i will need to have 2 short Cat5 cables to connect to the unused Onboard LAN on each PC. My question is, am i better to make the internal CAT5 cable cross over or just one of the short cables from the wall plate to a PC the cross over cable? I have movies stored on the upstairs PC, and i watch them on the downstairs PC on the TV and would like to stop the periodic glitch i seem to get when using the current wifi. I also get no shared PC on other days where the downstairs PC cannot be seen in Networking Neighborhood. I use a Dlink DSL504T as the modem/router, which i located in a cupboard upstairs. I have a 7db antenna outside the cupboard, which gives good signal to the upstairs room, but intermittent signal to the downstairs room PC.

Inside the wall, run straight through cable. If you are connecting computer to computer, you will need to make one of the cables from the wall to computer a crossover cable. If you are connecting the computer directly to the router, you can use straight through cable every where. -Ryan Adams http://RyanTAdams.com

So i will use a straight cable inside the wall. If i place a double outlet on the wall upstairs, can i connect 2 crossover cables into the double wall outlet, and connect 2 PC's to it from the one cable in the wall. I have 3 PC's all up. 2 upstairs next to each other(his & her) and 1 downstairs?

Pull two cables at the same time. Buy faceplates with dual (two) RJ-45 outlets in them and buy 4 RJ-45 keystone plugs (that fit in the faceplates you bought). Pull your 2 cables, punch them as straight through (either A or B standard at both ends) and make sure you test them. Then get a small switch to plug your PC's into so they can all be on the same network. Mind you, if it were me, I'd pull one cable, put the switch in the room with the dual PC's and then plug the solo PC into the switch via the cable in the wall. NOTE: Because in this case you would be plugging from PC to switch you wouldn't need a crossover cable. It's only when going from like device to like device (ie: PC to PC or switch to switch) that a crossover is required.

Almost every modern adapter hub and switch can adjust for the correct or incorrect cable. I make patch cables but that is just me so I don't have to fool with thinking much. "Best Practices", Event viewer, host file, perfmon, are in my top 10

Would a router do the same job as a switch?

Most routers (such as the WRT54G) have a switch built in. If you want to use it as a switch, log in to the routers configuration page and disable the router function. Then the 4 ports on the back will behave just like a normal switch. -Ryan Adams http://RyanTAdams.com