Ok it's more like my dad's computer. Yesterday I was using it to play minecraft and I tried to install the mob talker mod and ended up installing something called PalTalk. I closed PalTalk and gave up trying to install the mod. Then this morning when my dad was using it, when he typed in his password it said welcome for a split second and went black and said No Signal. It did this no matter how many times we did, and we were confused. I'm afraid to tell my dad that I tried to download something on his computer, because that might be the reason te computers like this. He has a lot of important files, and he's gonna give me a beating if he knew I had something to do with it.
How do I fix it?!
And sorry I can't tell you the model cause I don't remember.