Lost my network driver?

[Haydn]

I have a desktop pc that my kids use for there homework ,facebook and twitter .However I cannot get a net connection .I get the msg "cannot find proxy settings".Now we had problems with viruses that someone cleared for us but I can no longer connect or use the printer .I am no expert but im guessing the drivers have been lost ..Any ideas of what info i will need to find a driver i need and can i download it on to a mem stick and upload it back onto the desktop