Ok, have you done a fresh install of Windows?
Which version of Windows?
Was the new hard disk to replace a faulty hard disk that had Windows on it?
Or maybe a bigger hard disk for more space that took a fresh install of Windows.
I'm not sure about the picture problem, try changing the stock windows desktops and see if Windows keeps them. If it does, check the picture you're trying to use as a desktop, it may be corrupted.
As for Windows saying your code number is not genuine, it will have noticed the hardware change and that's why it won't let you activate.
This is a common occurence with Microsoft's Windows and is a Royal pain in the bot but you'll have to go through the telephone activation sequence to activate Windows.
I had to do this with Win 7 after just two months' use when I done a fresh install thanks to a Bios flash failure
The option to activate by telephone should be there when you attempt to activate Windows. I usually find it best to write the numbers down when they're read out by the Microsoft robot, then when you're given the option to check them, do so.
