As Eddy said you can change things with gpedit, I think that the default number of days is 90 before windows warns/suggests you should change your password. I'm not sure if you don't change it I don't know if it blocks access or is just a nag screen.
So it is possible to increase the number, strangely enough, if you set it to 0 (zero), it never askes you again.
But as has been said, it can seriously ruin your day.