Garmin Express causes high CPU load on Windows 10

I have the same problem and solved it the same way.

I installed Garmin Express 6.21.0.0 yesterday after purchasing an Edge 530, and my laptop has been looping between 1-2% cpu to 25% cpu every few seconds, and the laptop fan cycling up and down in time with that.  WMI Provider Host was the process looping the cpu, and following guides elsewhere, I could not isolate the underlying app or driver because the pid in the logs was no longer active.

Then I had a look to see what else I'd installed yesterday, remembered Garmin Express.  Quit the app and the problem goes away.  Start the app, the problem comes back.  So I have disabled it from running in the background for now.  I'm guessing there is a background process kicked off by Garmin Express that causes the issue, because the main Garmin Express pid didn't change and was not showing cpu usage, and was not listed in the WMI Host Provider errors.

I also noticed it installed some ancient ANT drivers from 2012, and very ancient USB drivers from 2007....  I uninstalled those, however the problem persists with the main Garmin Express app, so it is unrelated to the ancient drivers.

Perhaps better too post here - Garmin Express Windows 

Plus one! Same happens here.

Same here, I spent hours hunting Process IDs only to eventually find Garmin Express to be the root cause. Very annoying to say the least, especially as it's less than obvious (CPU use of WMI increases, and on restarting this Garmin express is not listed as one of the accessed programs).
Solved same as above, disable Auto Startup of Garmin Express.

In contrast to duncsimpson below Garmin Express was listed under the WMI Host Provider errors, but not reliably. So were a couple of other processes, went on a wild goose chase identifying various svchost processes, reinstalled a bunch of programs, updated drivers, etc. Fun way to spend a morning.

That was my path too :) It took me many hours to dig into WMI and obviously that task is not for everyone. In fact, all PCs around the world are affected but Garmin seems does not care. 

I've sent Garmin customer support an email. Not because I expect any sort of response (clearly this has been a known major issue), but I didn't want to suffer quietly. I guess I'm glad it's not just me who had to go through the suffering? :D
Their products are technically good, only reason anyone still uses them. They've got to be good, because their user interface and software in general is, in my personal opinion, a steaming pile of ****.
If Basecamp were the only option to manage routes/ tracks/ whatever, I would have jumped out of the window years ago.

There were recent GE update. Version number suggests that is major upgrade (ver. 7.0.0.0). Since then idle CPU load becomes even worse. Much worse - up to 80% load! That load substantially affects PC user experience, not to mention fan noise :) 

I have two Fenix watches currently connected to my Dell XPS 13 laptop, now over 4 years old. I have the latest Garmin Express. When syncing I can see CPU load for the task hit 20% or so, but at idle it is under 5%, sometimes well under. Sync has just completed and GE is running at 0.4%.

Rather oddly, however, I've just disconnected the watches and GE is showing spinning sync/search icons for the two watches. CPU is now holding between 7-9% while GE searches in vain for the missing devices. This does sound like some sort of bug once watches are removed. Terminating GE does, of course, solve the problem.

Same issue :(