Be warned that the Bluestacks software is an insidious little thing. It works, mostly, but 1) the stack is out of date (it was still on 4.0 last I used it only a couple months ago), 2) it comes pre-installed with an awful spammy launcher and superfluous game software, 3) it floods the system with superfluous extra processes, and 4) it even attempts to fool you into thinking you've uninstalled it when you haven't.
You can fix 2) by installing an alternate launcher, and in the case of 4), the main uninstaller does nothing, you'll actually want to uninstall the "BlueStacks Notification Center" to actually get rid of it.