I Messed Up The Computer

Last Friday night I added upgrades to my computer. I started to add other things and somehow lost my browser which was replaced with Babylon. I tried to uninstall Babylon to no avail. So, instead of giving up and waiting to call my provider, I played with the computer. What a mess I've made of things. Basically because I had no idea what I was doing. That was the tabletop computer, luckily for me I also have a laptop which I haven't messed up. Why isn't it easier to undo or uninstall something which you've accidently changed? It really annoys me. Tomorrow I will call my internet provider to see if I can restore what I've lost. Hopefully, they'll make it easy for me to do.