You contacted your ISP as MrH did? How ofen does the connection drop in your case? Firmware is up to date, right?

It is plugged in, all three lights are on, there is an Internet connection but it is coming up as limited. You can access internet with limited connection? Are you sure? Check IP address, default...

All TP-LINK powerline adapters can work together. No worries. There is no compatibility issue with them.

When connection drops out, how about status of powerline lights on those adapters? Check the status of local area connection. What's the IP address obtained? How does the connection work again?

All TP-LINK powerline extenders can work with PA211 and PA411. You can buy any one you like. But I'm afraid that it cannot provide or boost Wi-Fi to 3 or 4 rooms. You may have to buy more than one...

If you are not familiar with electrical wiring environmnet in your house, ask someone else like an electrician for help. Most retailers will allow customers to return in a period of time. You can...