SQL server2008 evaluation period has been handled

Start –> All Programs –>microsoft SQL Server 2008–> Configuration Tool –>sql Server Installation Center
–> maintain the –> version upgrade, then follow the prompts always point to the next, to the product key when entering
Development version: Pttfm-x467g-p7rh2-3q6cg-4dmyb
Enterprise Version: JD8Y6-HQG69-P9H84-XDTPG-34MBB

If the above operation also prompts the evaluation period has passed, modify the registry:
The "CommonFiles" value in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL server\100\configurationstate is changed to 3 to perform the operation again.

SQL Server 2008 installation needs to be restarted all the way:
Start –> Run –>regedit
Locate the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager location
Then right click on PendingFileRenameOperations in the right window, select Delete, and then confirm