Unknown computer on network

[footnick]

I have a wireless network with security enabled and 2 computers in the default WORKGROUP with password protected file sharing enabled.

There is a 3rd unknown computer named LDSPCHYXMP2J listed under 'Networks' apparently connected to my wireless network but in the GLOBAL workgroup.

Is this a problem and if so how do I fix?

Thanks

[footnick]

Panic over - its my wife's work PC !! I must have given her the network password at some stage.