Windows XP Home edition freezes on boot up. Can you help please?

I think the problem could be a corrupt registry. This can happen when loading new hardware or old software gets corrupted, in this case the old video card driver. If you can't boot in Safe mode then I would really suspect a registry problem. You can try putting the old video card in and do a restore. But I think you might be better off to format your hard drive and start all over. You also could have a virus. I have been through this type of headache before and I finally just started all over from scratch. One other thought, always make sure your power supply is good. Poor operating power supplies can cause all kinds of weird problems. Could be that your power supply is failing since it does run after a long break and then fails.