After working normally for years, several weeks ago my system started hanging during XP startup. After the POST and related preliminaries, the XP progress bar screen (the little window under the XP logo with the moving dashes) hangs and stops responding about halfway through. There are no error messages. Nothing further happens, even after waiting a long time, until I hit the reset button. I can then run XP in Safe Mode which works normally except of course I can't use most of my peripherals.

I've tried all the suggestions and remedies, including reinstalling from the original XP disc, short of invoking a technician to find the cause and/or remedy this problem, and nothing has worked. Is there a clue as to what/where the problem might be, how I can track it down, or what I can do to fix it?