You cannot use the following names with regards to files and folders in Windows without manually creating them in DOS using the md command followed by \.\ and then the path to the files/folders to be created. Reserved names:
- AUX
- COM1
- COM2
- COM3
- COM4
- COM5
- COM6
- COM7
- COM8
- COM9
- CON
- LPT1
- LPT2
- LPT3
- LPT4
- LPT5
- LPT6
- LPT7
- LPT8
- LPT9
- NUL
- PRN
You also can’t use Clock followed by other characters with NT4 and older.