I have a sony vaio vgn-b100 that worked fine on dial up. We recently got broadband available in our area and now when i try to turn the wireless switch on the computer flashes a blue screen and just keeps trying to reboot??? When the switch is off my computer boots fine but of course i cant get online with it?? Any suggestions??

When the machine keeps re-booting, it can be a sign that you have a hardware issue that prevents it from getting past the POST (Power on Start) process. In this case, there could be a hardware problem with the wireless board (or that part of the motherboard if built-in). If it tries to boot and then fails after 10 or 15 seconds with nothing showing on the screen, then that is probably what is happening. If it is getting further into the start-up process, displaying the vendor's startup screen or even getting into windows before failing, then you may have a driver issue or some other sort of software problem. If it is the first situation, then you might want to buy a usb wireless adapter and try that. They are pretty cheap and it might get you running.