A. When you get MAK keys for OSs, you might want to check how many activations you have left with the MAK. The easiest way to do this is to use the Volume Activation Management Tool (VAMT), which is part of the Windows Automated Installation Kit (WAIK) for Windows 7.
Launch the VAMT and select Manage MAKs from the Options menu. Click Add... to add MAKs. Once you've validated the MAKs you want, click the Refresh Remaining Count button. The software will connect to Microsoft and display the number of activations left for each key. Looks like I have quite a few more installs available for my server OSs.