I just went through the same problem. It got worse once I entered the code several times as it then said I had used up all of my activations!
I tried the solutions that Intuit provides, none of which worked. I spent about an hour and a half (WAY too long!) with tech support and finally got something to work. Intuit gave me a new code, which didn't fix the problem. What did fix it was a new download of the program for which they emailed me a link. I ran the download, told it to remove the existing program (support said NOT to remove it through Programs and Features), then ran it again to install the new copy. It worked and didn't even ask for the license code. I'm assuming it picked it up from the previous installation.
