I've noticed since installing the online IDE and plugin that my computer gets a bit bogged down. It's not particularly speedy in the first place. (i3 core 3.7Ghz 8gig ram 64 bit windows 10 pro) Anyway it seems to occupy between 6% and 10% of the CPU whether Create (or even Chrome) is running or not. Is there not a provision such that it doesn't run if Create isn't active. For now, when I remember, I manually pause it but seems to me that there should be a way for it to check if its needed before just humming a long. Or maybe there's something I don't know....
Usually that type of behaviour is caused by a security setting or software such as antivirus or similar.
For most people it does not cause an issue.
Occasionally some people may find they need to add the CREATE plugin to the exclusions provided by thier software.
It will also help speed up actual usage of create.
Its location is normally "C:\Users\USER\AppData\Roaming\ArduinoCreateAgent-1.1"
You may have to turn on the "show hidden folders to see it but most AV etc will allow you to browse to the location.
You can if you wish disable the autostart and run it from a shortcut.