I use a three year-old Acer Aspire V3-571-6698, running on Windows 8.1.
A few days ago, the Internet would cut off at random. To fix this, I would try to disconnect and re-connect from the modem, but in doing so, it would tell me that I can't connect to the network. After that, all available connections suddenly drop to only one bar, regardless of the strength before it happens (and usually, it gets five bars from the modem and a few nearby providers).
Restarting my computer fixes the issue, albeit only temporarily.

So far...
I've tried to reset the modem (both by sending refresh signals and unplugging and re-plugging), but it didn't solve the issue; nothing changes if I don't restart. The other computer in the house and any mobile devices don't experience the same problem, either, so I'm under the impression that it has to do with my laptop in particular.
Tightening the screws on the bottom of the laptop body didn't do anything either.
I tried to do a System Restore to several days prior to the problem arising, but it only fixed it for a couple of days.

At first, it seemed like it would only occur when I was running games that required a lot of computer strength, e.g. Minecraft and League of Legends, but this morning, the connectivity dropped when I only had two Google Chrome tabs open.

I am completely lost. Could someone please help me figure out what could be wrong?