operating system?

becoz con is refers to config file... thats why u cant delete..

I have no trouble creating a folder named prn,con in my documents on Vista. I do have a problem creating the prn.con folder as it is an invalid extension for folders. Are you trying to save as .com or ,com there will be a difference. Can you not name the folder something else?

Those two are included in the "reserved" device file names. Here are the others: AUX NUL COM1 COM2 COM3 COM4 COM5 COM6 COM7 COM8 COM9 LPT1 LPT2 LPT3 LPT4 LPT5 LPT6 LPT7 LPT8 LPT9. Windows will not allow us to create folder using these reserved file names. But I have searched on the Internet a way to name your folder using the reserved keywords but I haven't tried it because it's not advisable and risky, it can create ambiguity.

There are signs or punctuation marks that you can't really use in making/naming a folder in windows...that is natural!