Well, you tried F1 and that just took you to Windows. Try F10. That should put you into the BIOS settings. Search through the menus and submenus to see if there is an option to disable the thermal/temperature sensor. Also look for an option to disable error messages.
It may not solve your problem, but see if there is a BIOS update for that motherboard.
Run ''Belarc Advisor'' or ''Evererst Home Edition'' if you need to know your motherboard model number.
I have a Compaq Deskpro EN 4300. I recently upgraded the cpu in it from a Pentium II 400 MHZ to a Pentium III 550 MHZ. My new cpu came with a heatsink and fan attached. I had to hook the fan cable from the new heatsink/fan to one of my power supply plugs via a 3 pin to 4 pin fan power cable because my motherboard didn't have a 3 pin connector. It only has a 4 pin connector that resembles a cd-rom audio connector. My old processor had a heatsink cable that fit that connector. Now when I turn on my computer it stops on the bios page and gives me this error message: Thermal sensor from processor heatsink is not connected. After that, it ask me to press F1 to boot or F10 to setup. When I press F1 my computer goes on to boot and everything is ok. I don't want to keep pressing F1 for the rest of my life. So I am wondering is there any way to disable the thermal sensor because my new cpu with heatsink/fan doesn't use the old heatsink/fan connector also known as the heatsink thermal diode connector. If you know a way of disabling it or bypassing the error message, then I would be very grateful.