Windows 7 errors Please advise

I have a real dilemma here and am definitely in need of help. I bought Win 7 Ultimate for 2 installs over a year ago. I bought an Asus Laptop a year ago which came with the 7 Home and upgraded to Ultimate with no problems at all. 3 months ago I bought a Dell with 7 Home and upgraded it to Ultimate. Again no problems!
About two weeks ago I started getting multiple error message on both laptops my Windows 7 was NOT valid.
Two huge questions:
1] IF this is actually the case why would it be such a very long time before getting these error messages?
2] If I purchase a Windows 7 Home Premium version in a 2 pack what is going to happen when I try to install these on top of Win 7 Ultimate?
Any ideas are most appreciated. I hope I am not stuck with buying on OS all over again.
Both my laptops are running the 64 bit version.
Thanks very much in advance for any help or insight on

 

And exactly where did you get the key from?

If you got the key from ebay or similar, it was probably a MSDN key that got blacklisted; if you have an actual sticker with the key on it... then there's issues somewhere.

 

If these are legitimate keys, try and validate Windows, and see what happens. If still nothing, call up Microsoft.

If they are illegitimate keys, there is not suprise, as like Blaze said, it was probably an MSDN key that got blacklisted.

You could purchase Home Premium and install over the top of Ultimate. Actually, you said the laptops both came with Home Premium? You can just install that back on, as in most cases it will have a key on the bottom of the laptop.

 

I bought it on ebay. It came in the original packaging with the holographic image, key code, etc.
Man, it never occurred to me that the software could suddenly not work after a year, but I never heard of the blacklist situation either.
Now, I wonder if I get a two pack from Best Buy or another main seller online, what will happen when I try to load either Home Premium full install or upgrade? I have no clue.

 

You don't need to buy Home Premium again, as you already have an OEM key for it (I assume...), when you purchased the notebooks. If you don't have a disc, go here and download a legitimate copy and install it.

 

I am embarrassed to admit it but not sure how to unistall OS and then proceed to recover original OS which was installed prior to purchase.
Is there a summary of steps on this site?

 

Thanks I will do that.

 

You can't uninstall an OS. Also, to answer one of your questions in your OP, if you install Home Premium over your current OS, Windows Installation will ask you if you want to save your old Windows folder if you didn't format the disk. Up to you to decide if it's worth keeping it or not, but if you didn't save anything to it, I'd recommend wiping it.

I'd also recommend calling Microsoft and explain them your situation. I have a couple of friends who were in the same issue as you for Windows Server 2003, and they gave them new keys. If that doesn't work or you'd rather re-install Home Premium, follow the steps below:

Click the link that Joel posted and follow those steps to create a bootable media with Windows 7 Home Premium. Reboot into your bootable media (You may have to enable this in your BIOS if it isn't already) and follow the steps. After letting the installation do its thing, (Windows will setup the OS and reboot a couple times) there will be steps for you to input your settings. (Username, time zone, etc.) After that, you're in your OS.

I might be Captain Obvious here, but you should definitely backup before doing any installation. I made that mistake when I went from Vista to 7 on one of my machines.

 

Thanks very much to all