When I try to run CREO Parametrics it always says that I have to register the quality agent.
Unfortunately the quality agent was removed from the download package.
Where can I download the PTC Quality Agent?
You will probably need to run the install again. this feature is installed regardless of whether it is activated. It must have been removed after the install. At least, this has been my experience.
You might consider opening a case for this and letting customer service walk you through the steps.
Out of curiosity, what version are you using?
try to uninstall PTC Quality Agent. This piece of software does not have to be installed, when you use Creo Parametric.
The quality agent is located in the installation media (either CD or download).
For example, the 64 bit version is located here:
<CD or Download Folder>\install\addon\qualityagent_64.msi
As was mentioned, this is not needed unless you are running the academic version.