"I do not know how to use the computer."
Translation:Je ne sais pas comment utiliser l'ordinateur.
I think the 'comment' unnecessary in the french sentence. Though 'Je ne sais pas utiliser l'ordinateur.' is not the most literal translation, it captures the whole idea of the sentence.
"Savoir" is "to know" but when followed by an infinitive, it means "to know how" + (verb infinitive). The "comment" is unnecessary to express "to know how".
"Connaitre" is know in the sense "heard of" or being familiarized with the existence of something. You can "connaitre un logiciel" (know that a certain software exists) but it doesn't imply you know how to use it. It is much more frequent with people: "Je connais Jean." - "I know Jean" or "I've met Jean".
I think a decent rule of thumb is that you connaître a noun, whereas you savoir a verb.
In another item, some of our astute advisors (Sitesurf??) explained how, at least sometimes, the use of "comment" after the verb "savoir" is quite correct. It was very subtle so I am not going to try to reproduce it. Just believe them, it is sometimes correct.