I have iPhone4 with iOS5.0.1, itunes 10.7 (latest)

My Personal Hotspot does not work at all although i set to use USB or WiFi/Bluetooth mode

for USB mode my laptop wont just get to the internet with original usb cable
for WiFi/Bluetooth mode it cant be discoverable.

Anyone knows how to fix this? I have reseted my network settings, I have renamed my idevice to another name