Q1: Can I use a Windows Server 2008 CAL to access a license for Windows Server 2008 R2?
A: Yes, a Windows Server 2008 CAL can be used to access Windows Server 2008 R2.
Q2: Can I use my Windows Server 2003 CALs to access Windows Server 2008 R2 software?
A: No. You must either purchase new Windows Server 2008 CALs or have Software Assurance (to upgrade your CALs) to access instances of Windows Server 2008 R2. Your Windows Server 2003 CALs may continue accessing instances of Windows Server 2003 software.
Q3: If a user or device accesses a server running Windows Server 2008 R2 but is authenticating via a third-party authentication application (non-Microsoft based authentication), does the user or device still require a Windows Server 2008 CAL?
A: Yes, if the user or device is authenticating by any means to a server running Windows Server 2008 R2, it requires a Windows Server 2008 CAL.
Q4: If a user is only infrequently accessing certain protocols or services of the server software (such as Network Access Protection or Dynamic Host Configuration Protocol), is a Windows Server CAL still required? A: Yes, a Windows Server CAL is still required for such infrequent use of the server software.
Q5: Can I use a Windows Device CAL and a Windows User CAL to access the same server? Also, can I use a Remote Desktop Services Device CAL (RDS Device CAL) and a Remote Desktop Services User CAL (RDS User CAL) on the same Remote Desktop Session Host server?
A: Yes. Windows Device and User CALs, as well as RDS Device and User CALs, can be used on the same server.
Q6: Is there a difference in price between Device CALs and User CALs?
A: No. Windows Device CALs and Windows User CALs are priced the same, as are RDS Device CALs and RDS User CALs.
Q7: Are there any differences between the requirements for CALs in Windows Server 2003 versus Windows Server 2008?
A: The only primary difference with Windows Server 2008 CAL requirements is the following: If you deploy Windows Server 2003 virtual machines onto Windows Server 2008 R2, you do not require Windows Server 2008 CALs for your virtual machine users (you will still require CALs for your appropriate Windows Server edition, in this case for Windows Server 2003). This is only true if the Windows Server 2008 R2 in the physical operating system environment is running the Hyper-V server role