Q: Help Please!!!!

Can anyone please help i turn on my mac and its already connected to my wi-fi network but then after some time and it varies between5min to 2 hours but when its not connected i see no networks in menu when its searching and sometimes if i change my location if i click the wi-fi icon in the menu bar it says no internet connectivity and one time it said wi-fi: no hardware configured and it only does this a my home and in any place else it connects and stays connected so i would love to kno how i can fix this and is my mac that is the problem or my router and dsl modem or all in all any info about how to fix it and what you think the problem is?