Resolved Genuine Windows

I keep getting "This copy of Windows is not genuine" and my desktop is black. I have ASUS computer and the mother board and the hard drive was replaced by Best Buy. I couldn't find my backup disk so I had to order one from ASUS ($75.00). Best Buy installed it and all worked fine the 1st week then I got this not genuine message and BB told me to reinstall, which I did. All has worked fine since then (couple months) until today I get the same message and a black desktop. I did a google search and came across this site http://www.microsoft.com/genuine/validate/ but when I followed the instructions and clicked on "Validate now" I got a popup said my settings didn't allow me to download that file.
How do I fix this problem? This is not an upgrade, Windows 7 came on this computer, I gave all the information to ASUS (model, serial # etc) when I ordered the disk, but I continually have this problem.
I also get a popup that says an add on for this site failed to run, I pulled up manage add ons and there were NO add ons in the list.

Sorry if this is double post I did a search and did not find a thread on this subject.

 

Have you got ALLWindows updates installed?
Have you been able to go to Windows Updates? Neil.

 

After I posted this, it showed some windows updates that were not showing before. After installing them and rebooting the warning disappeared and my desktop came back. Not sure why it is doing this, but has happened more times that I can remember which is very fustrating. I have windows to update automatically so I always am up to date on that issue. Just not sure what is going on. I will keep this post for later reference should I have to revisit this issue. Thank you for your help, still confused as to why it is doing this.