Hi Ramez,
We are glad to know that you have chosen Windows 8 and thank you for asking this question on Microsoft Community.
Based on the description, it appears that you are unable to run Windows Phone Emulator after upgrading to Windows 8 Operating System.
The question you have posted would be better suited in TechNet Forums. I would suggest you to post your question in TechNet Forums for better assistance.
http://social.technet.microsoft.com/Forums/en-us/w8itprovirt/threads
For reference:
http://social.msdn.microsoft.com/Forums/en-US/wptools/thread/10877c5a-a0f4-4552-a28b-987562615189
I hope it helps. If you have any issues regarding Windows in future please let us know. We will be happy to help you.