I use Server 2008 R2 SP1 for test purposes and of course I do not have money to buy the full version of it. I have downloaded the trial version (6.1.7601) which is available to use for 180 days with complete functionality before it switches to the notification mode. The only problem with this that nobody tells you that the system tries to activate itself.
To disable the Auto-activation feature, follow these steps:
Click Start, type regedit in the Start Search box, and then click regedit.exe in thePrograms list.
Note: If you are prompted for an administrator password or confirmation, type your password or click Continue.
Locate and then click the following registry subkey:
Windows Server 2008
Windows Server 2008 R2 SP1
Change the DWORD value Manual to 1.
0 = Allow Auto-activation (Default)
1 = Disable Auto-activation
Change the DWORD value NotificationDisabled to 1.
Exit Registry Editor
Open Command Prompt and enter: c:\>slmgr -rearm
Restart the computer.