I have recently bought a "On networks" ethernet cable to use in one of the PC's in my house, the main internet-hub is connected with a Devolo Ethernet cable and plug (http://www.amazon.co.uk/dp/B0028QKNI8/?tag=hydra0b-21&h...) I took out the Devolo plug from MY Computer (not the main one) and put in the On Networks one, and I can't get internet! I'm worried if the Ethernet plugs have to be the same make or something. They have differnet mbps, the Devolo is 85, and the On Networks is 200. Please help, I don't understand what's wrong! Any walkthrough is greatly appreciated and will be tried, thanks.
You can use different brands of Ethernet cables, but they need to be the same wiring (usually 568B) and patch cables, not crossover (although gigabit adapters can auto correct that with their auto-MDIX).
Both of those adapters appear to be HomePlug AV 1 compliant, so they should work together, although they may each require different installation procedures -- some require the connected machine to use specifically installed drivers while others are plug and play -- you will need to consult the manual for that.
(While they are supposed to work together, I've always had the best results using the same brand, and preferably the same model, especially when using more than 2.)