The procedure you use to upgrade to Knowledge Center 12.1 depends on the version and type of installation you are upgrading from:
Knowledge Center 11.0 or 11.1: You can upgrade directly to 12.1. See Upgrade Knowledge Center from 11.0 or 11.1 for more information.
Knowledge Pathways 5.5 or earlier: You cannot upgrade directly to version 12.1. You must upgrade to either the Standard or Professional Edition 11.0 or 11.1 first. Be sure that you have converted all of your titles into Developer as well. You can then upgrade to 12.1. See Upgrade Usage Tracking and Knowledge Pathways Versions prior to 11.0 in the Upgrade guide for either 11.0 or 11.1 for more information.
Usage Tracking 3.6.1 and no Knowledge Center installed: You can upgrade Usage Tracking version 3.6.1 directly to Knowledge Center 12.1. If you have no version of Knowledge Center installed and are installing, not upgrading, version 12.1, you can use the installer and do both at once. See Upgrade Usage Tracking and Install Knowledge Center for more information.
Usage Tracking 3.6.1 and Knowledge Center 11.0 or 11.1 installed: It is highly recommended that you upgrade Knowledge Center to version 12.1 first. See Upgrade Knowledge Center from 11.0 or 11.1 for more information. You can then use the Usage Tracking Conversion Utility to upgrade Usage Tracking into Knowledge Center. See Upgrade Usage Tracking with the Conversion Utility for more information.
Note: You cannot upgrade the Knowledge Center User Import Utility. You must install the new version.