The Quadcore must be broken.
You can't consider a fresh slow computer to actually be faster than a corrupted good computer.
Yeah, it's kind of broken. Thanks to my stupid other brother, it had about 183 trojans on it.
Also, he downloads a lot of trash on that computer, which doesn't only take 98% of all the possible space, but also makes it slow as hell. I also believe it's overheating, because every time that computer is on, I can hear it from upstairs. By that, I mean it makes a LOUD noise.