This issue may happen when the files (Here it is WlanMM.dll)c orrupted or there may be bad sector or issues with your hard disk. So you may please click on start button and type “cmd” in search box , right click on cmd and'Run as Administrator'. Type “chkdsk /r” and hit on enter button. Let me know if any error found after running the checkdisk utility. I heard that WlanMM.dll file is network related patch file andyou may try to restore the file from Windows CD.
When I follow your instructions it says "This type of file system is NTFS. Cannot lock current drive"