I've bought an HP Envy 15 laptop, used, from Amazon. It had Windows 8 installed, so I tried installing Windows 7 instead. There were a lot of problems with that installation (the screen flickered, wireless wouldn't work regardless of what drivers I used, etc), so I installed Windows 8.1 instead. However, a lot of the drivers that came pre-installed on my laptop appear to be gone now.
For example, although there's a sticker on my laptop that says Nvidia GeForce, and I remember seeing GeForce as my graphics adapter in the dxdiag when I ran it on the original Windows installation, right now it says Intel HD 4600 for the graphics adapter. A downloaded Nvidia graphical driver doesn't install, because it says it doesn't recognize my video card. How can I find out what my graphics card is without opening my laptop up?