You can't create folder named CON in Windows - Reasons:

In MS-DOS, several special "device files" were available to aid in performing certain tasks, such as clearing the screen or deleting extraneous output from a program. In order to maintain backwards-compatibility, all versions of Windows up to and including Windows Vista will refuse to allow you to create a file with these "reserved" device file names. The following file names are reserved: 

  • CON
  • PRN
  • AUX
  • NUL
  • COM0 
  • COM1
  • COM2
  • COM3
  • COM4
  • COM5
  • COM6
  • COM7
  • COM8
  • COM9
  • LPT0 
  • LPT1
  • LPT2
  • LPT3
  • LPT4
  • LPT5
  • LPT6
  • LPT7
  • LPT8
  • LPT9

CON, incidentally, was a device file used to capture whatever was printed onscreen.
You have to study the subject of "reserved words" in windows. All the following are reserved words: The CON is a reserved word for the console CON, PRN, AUX, CLOCK$, NUL COM0, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9 LPT0, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9. 

Multiple Login in Yahoo messenger!

You can login with multiple ID's on the same yahoo messenger.

Follow these steps : ==>>

* Go to Start ==> Run ==>> Type regedit,hit enter

* Go to HKEY_CURRENT_USER ==>> Software ==>> Yahoo ==>> pager ==>>Test

* On the right pane ==>> right-click and choose new Dword value .

* Rename it as Plural.

* Double click and assign a decimal value of 1.

* Now close registry and restart yahoo messenger.

* For signing in with new id open another messenger .

Cheers!
PranaY