if you lowered the height, raise it, then tune the string and check for buzzing. make sure its about the same height as the other strings. if its still buzzing after you've raised it, then you might have a warped/bent neck. the simplest and easiest thing to do would be to take it to a music shop. they'll figure out whats wrong with it and fix it to the best it can get.

EDIT: if the strings on your guitar weren't meant to be tampered with, it wouldnt be manufactured in such a way so that you can tamper and alter the composition.