They are both correct and mean the same thing. I think "whole" is more common simply because it's shorter. :) Asking a lot of questions is good! There are plenty of people who enjoy helping.

'Entire' and 'whole' do seem to be exact synonyms, which is a pretty rare thing in itself. 'Entire' comes from a Latin root, while 'whole' has a Germanic source (originally meaning healthy/complete), so it does look like we have ended up with two words which do precisely the same job, and are interchangeable in all cases. The only exceptions I could think of were set phrases such as 'on the whole' and 'as a whole', and constructions where 'whole' is used as an adverb, such as 'The snake ate the mouse whole'. Apart from that - feel free to use whichever word you wish!

The same

they're pretty much the same, but 'whole computer' sounds more natural than 'entire computer'. here's one way to look at it; http://english.stackexchange.com/questions/9615/whole-vs-entire