Random pc server appeared, please help.

Hi guys, i was working away on my macbook pro this evening and i noticed there was a pc server showing up in my shared section in my finder ..... after searching how to delete this file (as i did not know what it was) it just disappeared.

I am worried incase this could be another computer gaining access to my macbook so if someone could explain what has happened i would be very grateful.

Many thanks...

The machines listed under the "Shared" section are machines on your network that are set up to share files. For instance, my Linux server shows up under there. Do you have any other computers on the network?

there are other computers connected to the wireless router, they have never showed up on my mac before though ..... im not very good with networks etc i just know how to connect to my router ... is this my network ????

i have worked it out ...my mother has been messing about as my step dads laptop wont detect a wireless router and the computer name is the same as the server name that was showing in my finder so its all ok now ... thanks anyway !!!