I don't understand the context. Does the principal come to my house, boot up my desktop and start looking through what I've been doing the past year? Or is this only applicable to computers brought into exams? If personal computers are used in exams, what accomodations are made for students who do not own computers?
As far as I know, computers are not required for tests/exams. But are allowed as 'aid'. Therefore, they won't care about one's desktop at home, but only about the laptop one will be bringing into the test/exam room.
So with this proposal, if one refuses to let the school check one's equipment, one can still attend the test/exam, but without one's equipment. Or one can be expelled.
