Windows 7: Not a genuine???

About four months ago i put windows 7 64 bit ultimate, that i got from my roommate, on my computer. it has worked great for months and just a few minutes ago i went to my desktop, and my background had changed to black and there is now the words "Windows 7 Build 7600 This Copy of Windows is not genuine." Why did all of a sudden that pop up? is there away to either make it genuine or a way to make the words go away?

If you didn't pay for it, no. If you did and can prove it, contact microsoft.

1. Click StartCollapse this imageExpand this image
   
   .
2. Right-click Computer.
3. Select Properties.
4. At the bottom of this window, click Activate Windows now.

As of just a short time ago, MS began a new improved method of verification that was part of an update. If your copy is not authentic, you just got caught by technology. If it is authentic call the MS, activation number.

Activate Windows 7 by Phone

the phone number can be found by following the steps in my previous post

How long ago is a "Short Time"?

I was updated on 2/23.

Ok, it was implemented on 2/23... From your post I thought something had changed in the last day or so, didn't want to miss out.
Regards-

If you did miss out, you missed nothing. The only benefit as far as I could see is for MS. I agree with their decision to implement the security, but if they bypassed me, I would not call to complain.

You must have missed the "Press Release". MS clearly states that piracy enforcement benefits us, not them...

Check you updates you will probably find that KB971033 was installed when your black screen started to appear.