Graphics Cards. How to update drivers correctly?

Basically all the information is on these pages I've been posting on, but yet to no avail, haven't fixed it yet. Basically, my graphics cards are showing lower settings than what they should be.

"During 5.4 I had gotten some computer problems, and my way of fixing them were just to resort to factory settings.

In the beginning, WoW would recommend me to play on High Textures, 8x Anisoptic, almost all high settings. I think I tried to update my driver, but it didn't work. So it then recommended me Triliniar, low textures, but it still felt like it was playing on my GTX 560m.
A CM told me to revert back to the dell drivers on the website. Which ones? Just the graphics, or all the ones that apply to me?
I'm afraid of going back to factory settings now, after going to the shop. It looks like they wiped all of Alienware, and now it's just Windows 7. I'm not sure if I should download Alienware Respawn because it might do something negative.
If I resetted my computer to factory settings, by the time I could play WoW again, it would recommend me to play on high settings again.
How do I fix this so I can avoid going restarting? I don't think I have any of my computer disks."