Getting the message "Windows could not upgrade the file NUL from c:\temp\glb1a2b.exe. Insufficient privilege:NUL. Windows could not upgrade one or more system files before starting" when booting into Windows. Press a button then Windows runs OK. However, the file mentioned above does not even exist and I would like to get rid of the message. I have been told by the user of the PC that no software has been installed recently.