If you’re a Colorado voter in Larimer County, you should check here to make sure you’re registered to vote.
For some reason, a lot of states have apparently been purging voters from their rolls, making their registrations “inactive”, et cetera. Colorado, believe it or not, had me listed as “inactive”. Fixing that took only an email sent from a Web form, so it was easily fixed (I hope it’s fixed, anyway). You might want to check to see if you need to do something similar.
I don’t have links for every other county in the country, unfortunately, so you may want to track down any applicable pages for your jurisdiction if you don’t live near me.