How can i get internet on my pc from my wireless connection on my playstation 3?

May be...

I have internet on my ps3 and i cant figure out how to get the internet connected to my pc and i have windows vista home premium

If u already have a wireless connection u need to use a dongle with the pc or run a ethernet cable from the router to your pc

A wireless router is the answer, like Netgear or Belkin.

well your probably using somebody else internet signal on your PS3

Just get a router and connect both your PC and PS3 to it.