iPhone 4.3 Personal HotSpot with iPad or PC
I had connection problems when trying to use iPhone 4.3 personal hotspot with a Wi-Fi only iPad or with a PC. My regular Wi-Fi router was off during my test. I even updated laptop's Wi-Fi drivers to the latest Intel Advanced Enterprise drivers (on Windows 7 64 bit) but the connection still refused to complete once the password was entered (same thing on the iPad).
The cause/solution was simple:
iTunes, by default, when it first connects one's iPhone, gives it a name in the form of "UserName's iPhone". (BTW, that "apostrophe s" in the iPhone's name is displayed incorrectly when the SSID is displayed on a PC.)
In iTunes, we can rename the iPhone just by clicking on its name on the left pane. So, I renamed my iPhone without that "apostrophe s".
I can now use the HotSpot feature of my Iphone 4, when needed at specific locations, with my iPad and my PC without problem.
Hope this can help others.