Could someone please help me with a computer problem,Im tearing my hair out here.?

I have two laptops,and I connect to two unsecured wireless networks.A few weeks back the secured networks suddenly disappeared from my list of networks.Thing is I bought a 7inch notebook and the networks are available on that.I took the laptops to the computer fixers who charged me 70 quid to mend them.They worked in the shop but once I got home the unsecured networks did not show up on the list.I know they haven't been security enabled as I am connected to it now.I phoned the shop and said it still wasn't working and the greedy buggers want to charge me another 50 quid to come to my house to put the two unsecured back on my computer.Does anyone know what has gone wrong?I manually put the names of the two unsecured networks onto my preferred list but they still dont show up.