My laptop won't connect to the internet? - 1

I have a Toshiba laptop. Last week, I was on my control panel uninstalling a few programs because the Toshiba Checkup app thing told me to do this regularly for things I don't need. Anyway, I think I must have accidentally deleted something essential for connecting to the internet, because after I shut down the laptop and turned it back on the next morning, Mozilla Firefox had a screen that said it couldn't find a connection and suggested a few things for me to try and get it back. I tried all of those. None worked. One and two were simple, telling me that I should correct my spelling or connect to a network, but three told me that maybe a proxy wasn't able to get through the firewall, so I tried that. I made sure Firefox had access beyond the firewall, and STILL it said it wasn't able to connect. It had been doing this for he past couple of days. Then I eventually restored my computer to go back before I had fiddled with uninstalling, and I was able to get online. After I closed Mozilla, however, the same message told me it wasn't able to connect when I opened it again. So I restored it once more and here I'm, taking advantage of its internet access while it lasts. I don't think it's our router, because all of my other devices can connect to the internet just fine. (other laptop, iPhone, iPad, etc.) Please, if you know what's wrong, help me get my stupid laptop to work again! XC
PS- I can add screenshots of anything if anyone needs them.

Its because you are you using the wrong Firefox edition for Toshiba windows computer. It doesn't respond to the modem all the time because of processing lag. I think this is the right version: https://www.google.com/...e/browser/ or try https://www.apple.com/...om/safari/ (i used a url shortener because the hypertext was too long)

Try another browser and see the difference