Oh sorry for the multi-posting.
I don't know how to explain the problem but it goes like this. I was browsing the internet and suddenly my laptop gives a 'zzz, zzzz' sound and then suddenly whatever video or songs i'm listening or watching will lag and my wireless connection will be switched off (using Windows 7 so there's a red cross on the icon). There's no other way to connect the wireless back until i restart the laptop and sometimes it happens again after i restarted my laptop.
I don't really know what's the source of the problem. Sometimes it may occur when i'm browsing the internet (normal sites like facebook or twitter) or it may also occur when i'm watching videos.