Hello:\r\nI have a computer running Windows XP

Hello: I have a computer running Windows XP Media Edition SP2. Several weeks ago, I started experiencing boot up problems with my computer. It stops booting in normal mode. It will boot in safe mode. When booting (in normal mode), the windows logo would appear and the colorful dot would flash across the screen; however, this is as far as it would go. I have booted in safe mode and using “msconfig” configure it to boot up using the bare basic boot up (Diagnostic Startup). Still it will not boot up in normal mode. I have scan for viruses, malware, adware, etc… and find nothing. I have also scanned my HD for problems; no problems were found. I use Acronis 2009 to backup my hard drive (HD). I loaded an older image of my HD, and the older image would work for several boot ups; however, I discovered that if my computer remains on overnight, the very next time I tried to reboot, it will not boot in normal mode. I even tried loading my oldest image; however, the results were the same. I can even load the latest image that stop booting in normal mode and it would work fine for awhile; however, after several hours, it would stop booting in normal mode. To me it appears that I have a virus or something that times out after awhile and prevents my computer to boot normally. Microsoft web site was no help. I am to the point of deeply considering reloading my computer with Windows 7. Does anyone have any ideas?