The 4 is pretty good for this.
1. get a toothbrush and clean the USB slot in the phone and get a new usb cable ... as they wea rout quickly.
2. go into the phone settings and change it to "use the phone as a media device".
3. make sure the fone is on and not locked then connect the cable to the lappy ... it should show up.
Away you go.
If you still have problems try the KIES software ... but I find it a bit of a dog.