Cant change wallpaper in win 7 64bits Ultimate

Hi,
First of all, i searched the many forums for an answer and did not found any that resolved my problem.

I will start by telling what i did to better explain.

I had the OS win 7 ultimate 64 bits installed in a IDE HD, and it never gave me any trouble. Because i'm a bit of a speed freak i decide to install a SSD and install on it the OS (same copy of the other one). I started by changing the motherboard to AHCI and in the sequence boot placed the SSD as the first to boot and the old IDE (still with the OS installed) as second. Everything went smooth. Made every ugrade and update needed without a problem. remove in the msconfig the old IDE record so it does not dual boot. Its running like silk. So far so good.

the problem was when i wanted to change the wallpaper. It doesnt assume it. not even the default ones (i can only change the solid colors).

I tried everything from changing the registry keys, creating new users, deleting the trasncodewallpaper, changing the local policies etc. etc. etc. Nothing seems to work.

The only thing it is giving me a error is the windows index rating or something like that. It is unable to finish it, gives some kind of error. dont know why. I have the latest everything installed. Latest games and movies run perfectly.....

Need fresh ideias to fix my problems...... getting desperated!