does each stick on its own work ok? and does the computer boot into windows ok even in safe mode and then crash or restart later or does it not boot at all? what error is displayed when it crashes? what operating system.
im guessing xp. if so and windows starts then to to get a useful error displayed click: 'start/control panel/system/advanced/start up and recovery/settings' untick 'automatically restart' then when it crashes note down the error displayed and look it up via the 'search (Kb)' box click here maybe
mobo specs click here