I just got a new phone (HTC Desire) running android 4.4 and I am trying to set it up for development but I can't find the build number in order to tap it 7 times in order to reveal the development options, I've already been able to and had much luck with other phones but this one leaves me confused.
What model of the HTC Desire do you have? For the 501, the build number should be located under: Settings -> About -> Software information -> More
. Have you looked there?
Per Cricket's FAQ: http://www.htc.com/us/support/htc-desire-510-cricket/faq/2/