How do I change a KMS key to something else?

I am using Windows XP Pro at my office. I had bought a upgrade of Vista Business edition. It is a multi user pack. I can use the same on 10PC. I am trying to upgrade the system but stuck on KSM key. The system fails to find the kms key. I cannot activate all the editions on my system. How to fix the same.

I think KMS needs a minimum of 25 system to be activated at a time. And I think due to that you are getting the problem. If it is possible for you to find a option to convert the KMS to MAK then you would be able to work on the same. You will need to contact Microsoft for that.