Update server 2003R2 to server 2008

 ERROR:- uninstall the Windows PowerShell 1.0

When you start the setup ,it check the compatibility and gave some error that uninstall the Windows PowerShell 1.0 and you never found the KB  in windows add remove components.

the easy option is to download registry crawler and search all the entries contain PowerShell ,select all the entries and remove.
Now go to windows\system32\powershell and remove that folder. and also go to Windows\SysWOW64\Windows\and remove powershell folder.

Now you are ready to go for up-gradation to server 2008.