Virus encrypted all my personal files... how to get them back?

I hope I'm not posting in the wrong forum, but I'm a newbie and in serious need of help. I had a virus on my computer that Norton helped me get rid of, but the virus left all my documents, music files, photos encrypted with a .micro extension. The tech said Norton has no fix. Is there anywhere I can go to find a fix to decrypt my files? I am running Windows 7 and the virus left me a very rude message that I would have to pay them to get my files back. I certainly don't want to deal with those folks! If anyone can help me, thank you ahead of time.