Graphics Driver not installing

So I recently got back my computer from Dell(after sending it o them 3 separate times). Basically I got the thing back with a new Motherboard, BIOs, and memory chips. Obviously with new hardware means I have to to reinstall its corresponding software.

Sadly I have to reinstall IE & WMP since they either wouldn't launch or would act very funny if it could lunch (don't know if it's relevant to the problem). I reinstalled both just fine - I used the new IE to download all ~70 updates. I repeated updating until I had nothing more to update.

Now to the graphics driver. I tried popping in my Dell Drivers CD to install my graphics driver. It gave me an error someplace along the way saying how data is either missing or corrupt. So, w/e I go to Dell's drivers&support webpage, punch in my service tag, DL the correct Nvidia 6800 driver, install it, and my screen finally looks pretty.

Now for the broken parts. If either I reboot my computer or keep it on too long with its lid shut (it's a laptop) my screen will shrink back to it's normal size. What's weirder is that when I right-click my desktop & go to Properties, all I can see are Themes - NO TABS ANYWHERE(especially after installation)!

WTF can I do?