There is a way to upgrade Windows 7 professional to Windows 7 Enterprise that is not officially supported from Microsoft.
here are steps that you should take:
1. Create a .reg file and double click on that with following text.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"EditionID"="Enterprise"
"ProductName"="Windows 7 Enterprise"
2. Insert 7 Enterprise DVD and launch it upgrade option.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJ25W18MNgNI8EV3f-AHU2ULC9_qaMv6vpZ6ZOZqte0aT6DWvTCp08GZxy6RELPoWzmtcJQcQuUeIj07ufqebR-bGf3XGpTyfvdJl76qMijvdbpuGDriXv-TqtIo9CF1uTyE2M0Cs-_Ex3/s640/Win7ProfessionalRegistry.gif)
[original article http://richardfleming.me/upgrade-windows-7-professional-to-enterprise/]