Do whichever course you want. No course will teach you how to work with computer hardware as such, because by the time you finish your degree that info would be redundant.
I enjoy building and stuffing around with computers, and I'm doing Civil Engineering. If however you like software and programming, then look at comp. science/comp. engineering/software engineering.
building and servicing computer hardware sounds like something you get taught in tafe or as an apprentice. If you read here there are 2 possibilites either a IT degree with a major in digital design and systems or a degree in computer engineering