How do I reset my computer. I changed it 6 months ago, and now it wont reset on 1997 Mazda Miata MX-5

I pass everything else except the computer test. I have driven it 250 miles hoping that that will reset it but no luck....I need to pass in order to get my license tag....What to do?

Asked by for the 1997 Mazda Miata MX-5
try disconnect battery for a few minutes. comp. should go to default. another weird one that works sometimes is to pull engine light. don't know why that one works but some times it does the trick.