I had problems with files i got from internet. Sometimes cannot delete the file or cannot delete a registry as a part of the file/s. I tried several methods, DOS mode, delete utilities, etc, but to no avail.
What i did is creating a new account( it can be name whatever ). Put or moved the culprit file/s inside the new account and delete the account. I dont know if i did the right thing, but i did it in frustration deleting undeletable file/s. Hope this method can help others.