It happened I installed windows 7 on my pc that had windows xp professional and left without updating it for about one year until I decided to upgrade windows 7, but every time I restarted the computer after an update back to the same windows xp professional way they had left before installing windows 7. Do not use the dual-boot it started windows 7 and xp normally without any error message. Do not believe it when it happened, but that's what happened. Now I upgraded to windows xp and flash player turned off and returned to windows 7. I disabled all updates, because I know it can happen again. If someone could help me please help me. Thanks

Unfortunately I cannot find the current status from your description. 1. If you need both operating on your computer then use EasyBCD to configure boot process. 2. If the targer operating system is Windows XP Prof only, then there is no downgrade path except for reinstallation. Regards Milos

How about not running a dual-boot! Run win 7 with a XP VM.

Hi, From your description, Windows 7 has been downgraded to Windows XP after installing the update and rebooting. However, based my research and knowledge, this cannot happen. Could you please assist me collect the screenshot of the problem and let us know which update lead to this problem?Kim Zhou TechNet Community Support

I appreciate all answers, I know it's hard to believe, I'm not lying as it happened, unfortunately I can not show the problem because I've done all windows update so far. But when it comes other updates, I'll be tuned in order to record a video to show me and I will report if this happens again. Sincerely,