When trying to activate Office 2010 with KMS you recieve the error: 0xc004f038 (Unknown Error).
According to Microsoft, this occurs when the client activation request count on the KMS host is not high enough for client computers to activate
Relevant error code: 0xC004F038
The Office 2010 KMS host must receive activation requests from at least five Office 2010 KMS clients before KMS clients on that network can be activated. If the KMS host does not receive more than five requests, KMS clients will not be activated. If you deploy Office 2010 to more than five computers, their initial activation requests will be used to build up the count. If activation fails, the computers will attempt activation two hours later. At that time, if the KMS host has a sufficient count, activation will be successful. To trigger activation manually on the KMS client, run ospp.vbs /act. For more information about the ospp.vbs script, see Tools to configure client computers in Office 2010.
On the KMS Host, using an elevated command prompt type slmgr.vbs /dli to view license information.
Troubleshoot Volume Activation: http://technet.microsoft.com/en-us/library/ee624355.aspx
Troubleshoot KMS Host: http://technet.microsoft.com/en-us/library/ee939272.aspx
Update Office 2010 from MAK to KMS: http://kb.wisc.edu/page.php?id=13994
Volume Activation Management Tool (VAMT) 2.0
Download Volume Activation Management Tool (VAMT) 2.0
VAMT 2.0 allows administrators to automate and centrally manage a range of activities related to Windows client, Windows Server, and Office 2010 activation.
Including Office 2010 KMS Activations.