Computer speed-up and repair
Speed-up and repair of computer
Is there a difference in meaning between these two phrases? Which of these phrases is more suitable for the sentence:
I offer ___________________.
Short answer: Of those two, I would recommend using the first one.
I offer computer speed-up and repair
Footnote: If you wanted to use the second one, use the plural.
I offer speed-up and repair of computers
(I still think the first one sounds better, though.)
Fun fact: When a noun is used as an adjective (as it does in the expression computer repair), that is called a noun adjunct. You can read more about noun adjuncts on Wikipedia.