I have two laptops a Lenovo and a Toshiba. I don't use either very much however the people that do use them use them to watch things online which has a lot of pop ups and to browse. Both are windows 8 and the Lenovo is about a little less than 2 years old and the Toshiba is a little under than 1 year old. The Lenovo is very slow, has no anti virus or anything and google chrome (my preferred browser) doesn't open although it is installed. The Toshiba works fine a lot of the time but sometimes when I move it and its not on a flat surface (I usally keep it in one place) the screen just blacks out at certain angles until I move it to the original angle. I do not have the patience to endure this anymore. I have never formatted a laptop but it seems pretty easy from what I've read online or should I take it to a professional.
Added (1). And what is the worse that could happen if something goes wrong with the formatting?