You may have plenty of ram. But are all the sticks good?? I would suggest running memtest.
Check that you have working fans , a adequate well working PSU,
This statement from you: "sometimes even earlier before windows begins to boot up"
Makes me think a POST problem , rather than a OS problem.
im running windows xp, and suddenly it has started "freezing" upon startup and sometimes even earlier before windows begins to boot up.
its not a memory issue either. I have plenty of that
Im just wondering what I can do, I would like to try a system restore but I usually dont have enough time to attempt one before the computer freezes.