Don't you hate it when a family member or a friend gives you a code redeemable for an iTunes copy of a movie, only to get the following error message - "You must insert your Digital Copy DVD into your computer in order to redeem this code."?
These types of movie redemption codes are commonly referred to as "disc based" or "XML based" digital copy redemptions, and are rarely seen with newer codes. In fact many "disc based" or "XML based" codes will have an expiration date that has passed (ie: expired) and yet many of those codes will still work, albeit for an SD version of the movie.
There are workarounds for both PC and MAC, with the files and easy to follow instructions posted generously @Blu-Ray
.com Forum: No longer need XML files for iTunes Digital Copies
I have personally used those instructions to redeem dozens of disc based iTunes movies without the required discs!
Also, if you aren't lucky enough to have generous family members or friends, there are places to get "disc based" or "XML based based iTunes movies on the cheap (for details check my previous How-To "How-To: Get Movies And Television Seasons On The Cheap!
As always, use any of the above methods at your own risk as although I have personally used these methods your experience may vary and I take no responsibility for your use of the information provided.