Suppose, I have purchased a DVD of movie and my PC's DVD drive has problem. Is it legal to copy content the DVD of movie to a flash memory and then use it on my PC?
17 USC 117 says:
(a) Making of Additional Copy or Adaptation by Owner of Copy.— Notwithstanding the provisions of section 106, it is not an infringement for the owner of a copy of a computer program to make or authorize the making of another copy or adaptation of that computer program provided:
(2) that such new copy or adaptation is for archival purposes only and that all archival copies are destroyed in the event that continued possession of the computer program should cease to be rightful.
But this "archive right" is specific to computer programs, aqnd does not apply to other digital content.
Making a copy to avoid a malfunction is almost surely fair use. But format conversion as a tool for "space shifting" making content available on a different device or different kind of device than the distributor intended the copy to work on is not so clear. Courts have been divided on this kind of use, and there is no definitive Supreme Court ruling in the US.