You don't say how old your daughter is but the reasonable assumption is teenage. They fill the computers with all sorts of buggy crap from various messenger sites, silly icons, and so on.
When I gave my son my old desktop six months ago it was taking about 40 seconds to boot up, from power on. It now takes 5 minutes and runs like a tortoise. Of course he hasn't downloaded anything or been on any crappy sites ..... much. I've told him that when this one dies, he pays for the next one, and I note a different attitude now!