[ubuntu] Start Up Issues, Errors

I have been trying to clean out my computer. Essentially restoring it to it's original, fresh state. When I attempt to reboot the following happens: Black screen, white text. Scrolls really fast all the way down the screen. I did some research, and booted with pressing the shift button. Then updated grub. Then did the reconfigure package files. The issues still persist. (I am thinking about uninstalling, and installing lubuntu) However, I am on a dedicated path to leaing everything that I can about linux. I would much rather seek and find the answer to what is causing this issue, and fix is manually. I keep searching, reading what I think will fix it, then it tus out this isn't fixing it. I believe that I have some type of malware on my computer. Sometimes it will say on the network manager, that it is coected to some strange etheet network - that I have never been coected to. I don't ever use etheet on this computer. Please, any and all help will be so greatly appreciated. If there is an intruder on my computer I want to find him. Also, when I updated the grub boot loader, when going into "recovery mode", I noticed that there were 2 seperate versions of ubuntu. 1 normal and 1 recovery mode for each. Seems this could be just past updated versions?