=rand (200,99)
Then hit Enter Key.
There is it!..
It all began when I try to create folder name CON and I got an error message "Cannot create or replace file: The filename you specified is invalid or too long.."
I try to search the net and found out that not all names are possible to use when creating a folder or file names. Here are the list; CON, AUX, PRN, NUL COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8 and LPT9.
The explanation is that, these names are reserved for system device. For more information please check out the Microsoft page.