i dont know what the problem is exactly......
but i had a problem with an mkv file which just wont be able play,rename or delete.....
the only thing that shows when i right click is send to,open with etc.
so i was searching the internet and FOUND THE SOLUTION FOR MY PROBLEM.
i just renamed the folder of the mkv file and the mkv file started acted normally.
now i am able to play it and do watever stuff i want
JUST RENAME THE FOLDER OF THE MKV FILE
i did not discover this solution but i found it on other forums where the user has the same problem with a jpeg file.he just renamed the folder and it worked for him. i done the same and it worked with me too...........