I have purchased the game after a trial period, and cannot get to a point where I can enter my registration key.
Whenever I click on the Sudoku icon on my desktop, I get a reminder screen, with two options - check price / buy (which I did) and start the evaluation version. If I then choose this option, the message is:
"Your system clock appears to have been set back, possibly in an attempt to defeat the security system on this program. Please correct your system clock before trying to run this program again. If your clock is correct, please contact the author of this program for instructions on correcting this error (report code CCB-F)."
Can anyone help? I have tried downloading the trial version again but this doesn't work either.