You can control whether the file is set as sparse or not by running (from an elevated command prompt) fsutil sparse setflag <filename> 0|1
To turn off the sparse setting, run:
fsutil sparse setflag YOURFILENAMEHERE 0 To turn it back on, run:
fsutil sparse setflag YOURFILENAMEHERE 1 and to query it:
fsutil sparse queryflag YOURFILENAMEHERE I found this by trial and error and a search on TechNet - I don't go around setting or unsetting sparse files so I can't speak to any risks from doing this, other than the file(s) will take up much more actual space than they might have otherwise.