oddlyrelevant

The OS has locked your file. You need to use an unlocker to remove that lock and then delete it.

1. Download process explorer from microsoft.
2. Extract it and run the exe as an administrator.
3. Press Ctrl + F and search for the file you are trying to delete.
4. Once the search completes, it will show you the process that is using the file.
5. When you click on it, you will find the corresponding process and dlls in the bottom section of the process explorer window like this.
   
6. Right click on each process and select Close Handle for all.

After closing all the processes, you will be able to delete the files.