I am taking a class which requires Adobe After Effects. It is available in the lab but it would obviously be easier to install it on my MBP. he said to wait till April to download the trial because its only good for 30 days, and we will need it most then. However, Im wondering, if I download it and use it for 30 days, then uninstall it, then try re-downloading the demo in April, would it not work? Does it leave some sort of file on my computer that would prevent it from running again in april? And if so would there be any way to delete that file?
Yes, there is some type of mechanism so you can't install a demo twice. While I don't know for sure how to get rid of said mechanism (it's probably against the user agreement too making it not exactly legal), you can always reinstall OS X. That would DEFINITELY allow you to install it again The easier way would be to make a clone prior to installing. Or just wait until April like your teacher suggested.
Here are two sites that may help you chubbywagon: One is for archive and install. http://support.apple.com/kb/HT1710 http://support.apple.com/kb/HT1544