"to be interested in XYZ" is more common That participal adjective (to be interested..) + in (preposition) -- they go together i.e they collocate For example: I am not as interested in music as I am in art. NOT: I am interested about music... I am interested in attending your class. NOT: I am interested about attending... Are you interested in learning English? NOT: Are you interested about learning English... "interest + about" is understandable but it's less 'standard' It's not wrong, it's just less common than "to be interested in XYZ" If you said "interested about" it sounds like learner English (to me) If you say "I am interested in XYZ" it sounds more natural (to me) I am not a believer in prescriptive grammar (strict rules about what is "correct" or "incorrect"), but There are lists of these participal adjective collocations: interested in concerned by preoccupied with determined to bored with tired of sick of There is a comprehensive list here: http://www.bedavaingilizce.com/prepositions/adj_pre.htm

Variants and it depends if you start the conversation or reply to something said. you start the conversation I'm interested in your programs -- this is the most commonly heard . You might hear "I'm interested about your programs" but it would be a bit strange. It is more likely that you would say I'm interested to learn more about your programs. (or hear more) If you replied to something already said, then both of your original sentences are good.