oddlyrelevant

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

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

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