remedies for 90 days test-use

I bought the cs5 premium 3 years ago and seldom use it. Until recently I installed the software and it said it has 90 days test-use. I remenber I installed it 2 times in computers which have been formatted. I got similar situation about a year ago and I phone adobe the guy there charged me 99 canadian to fix it. And now I have the same problem again. What is the remedy?