I have a Dimension 2350 running Win XP Pro. I had a cooling fan that was squeeling so I ordered a replacement from Dell (exact same one as I took out). When I put the new fan in, now as I try to boot up, I must hit F1 to get through the boot process to get windows started. I think it may think that there is no CPU fan detected, but I have the fan plugged in and hooked up just like the one I replaced. Any ideas?