Window 7 Not Genuine...But It IS!

I bought this computer brand new about a year ago,not quite a year to be exact. It came installed with Windows 7. Well, for some reason,which I cant remember,after about 2 months I did a full restore using the disk that game with it to reinstall Windows 7. It also came with a driver disk to reinstall drivers but I never ran that. After about 6 months maybe, I got the water mark declaring my Windows 7 was not genuine. I called Microsoft and they confirmed that my lic. was real and after being transfered 5 times finally told me call Dell. I did and they did one of those things where they hijacked my computer and updated my bios. After clicking on the properties of my computer,my lic. showed up. Well just 2 days ago I installed a windows update KB976902 and yet again...watermark. I just did another reinstallation and my lic. reappeared. I started to think that I may have installed the KB976902 update the last time this happened. Any ideas how this is happening? It wants me to update that same one again and I just hid it. Might it have anything to do with not reinstalling the driver disk as well? Keep in mind that this IS a genuine copy of Windows 7. Any advice would be greatly appreciated,as always.

if its legal with key then obv sum1 using ur same product key like happend to me i use legal bought seven but i have to use loader coz i installed on a few diff pcs

If you ever do and out of box restore again keep in mind not to install these 2 updates, at this time the are optional updates, and you can hide them, but once installed they are there to stay. These updates are for Microsoft's benefit and not yours, and as you can attest they cause issues even on a legit copy.
KB971033
KB976902

I know you probably don't want to hear this but the easiest solution is to install a good boot loader, and you should be good to go, otherwise stay on hold on the phone forever and wait for them to hijack your computer again. If it was me I would just do a new install with a bootleg that way you don't have all that bloatware installed.

Good Idea James,Thanks
I actually did install the KB971033 update though.
But after reading what you said I uninstalled it.