How to disable Show Characters box in wifi security in windows 7

[tito_66]

sometimes I let my friends to use my laptop but unfortunately they can see password of my wireless router which my laptop is connected to by going to this wifi network Properties and then to Security and then check in "Show Characters" box..so is there any way to prevent them from seeing my wifi network password in Windows 7 ??

Thanks in advance

 

[tito_66]

any help plz ??