Every time when I have had corrupted file which I could not delete (or do anything), this simple trick has solved the porb:
make a blank .txt file or what ever file and store it somewhere else than where the corrupted file is
rename it exactly as the corrupted file (incl. extension)
copy created file to folder where the corrupted file is replacing the corruted file
After that you are able to delete the file
Worked for me every time... :