Hi
If you are upgrading a production system, you must order an upgrade from Cisco.
If you have UCSS (i.e. free entitlement to upgrades) do so via the Product Upgrade Tool : http://tools.cisco.com/gct/Upgrade/jsp/index.jsp
If not, you'll need to speak someone about ordering the upgraded software.
Either of those should result in you getting a new license PAK by mail or email which you can then register to get a license file.
If you just upgrade using a downloaded ISO, and move up a minor or major version (e.g. 8.0 - 8.5) you need a new license after the upgrade or services will stop.
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Aaron
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