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Hi,
When I come back to my laptop and it's gone into idle mode (screen off) I can hear the fans running fast, but as soon as I move the mouse the fans die off. I tried to figure out for a while what was happening and eventually set up perfmon to record what processes were running. I discovered that runs at 50% CPU continuously while the machine is in idle which is ridiculous for something that shouldn't be doing anything much (I'd upload a screenshot but there doesn't seem to be an option anywhere). Looking at details in Task Manager the PhoneExperienceHost.exe process has used twice as much CPU in total than any other app, even though I haven't used it in the foreground.
I do use Phone link to connect to my phone, but it's in the background (system tray icon only) and shouldn't be doing anything most of the time.
There's nothing related in Event viewer and I can't see anything in Scheduler which might trigger it.
I have tried uninstalling and reinstalling the Phone Link software.
The machine says it is up to date for patching.
I've searched for anything related to this issue and found nothing helpful so either it's only my machine, or other people don't realise it's happening as it only happens when they can't look at it!
Any ideas on how to fix this so it stops using my power (obviously uninstalling is not an option)? (TBH though, I expect it's something built into the software and can only be fixed by MS)
Thanks,
Jon W
Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.
Many thanks to this thread for providing the answer as to why my laptop fans run high when it goes idle!! I figured it was unique to the make/model of my laptop, so I was on the wrong track for too long, looking at BIOS settings and cursing the laptop manufacturer.
Disabling / removing my phone from Phone Link has solved my issues!! What a poorly implemented good idea. I'm back to using Pushbullet.
PROBLEM SOLVED!!!
Also when you close the app from taskbar, process not terminated (and when your PC go in idle, it will use CPU again) and you must start task manager to terminate process "PhoneExperienceHost.exe"
In Process Explorer you can see that thread named "dwmcorei.dll!LiftedCompositionEngine_Initialize" loads your CPU![Image](https://learn-attachment.microsoft.com/api/attachments/a472b581-07f4-4480-bc8e-9a91a97be3b8?platform=QnA
By the way, another strange thing is that this dll file names "dwmcorei.dll" has version 22622, although the PC has build 22621 (not downgraded from 22622/22623)
Also when you close the app from taskbar, process not terminated (and when your PC go in idle, it will use CPU again) and you must start task manager to terminate process "PhoneExperienceHost.exe"
In Process Explorer you can see that thread named "dwmcorei.dll!LiftedCompositionEngine_Initialize" loads your CPU. I didn't try to kill off PhoneExperienceHost using Task Manager at that time, instead my first response (after taking the screenshots) was to "Restart" the laptop. That was sufficient to clear my problem and I moved on. I am *very* wary of killing off Windows processes -- especially ones whose threads can gain kernel privilege -- and would do so only if it was my last-hope method for gaining enough system resource to save my currently-opened files to disk.
It looks like you're running Process Explorer from a command line. I'm using the GUI from https://download.sysinternals.com/files/SysinternalsSuite.zip. Now that I have a current version (I had been using v16.21 of 20 Oct 2018), I'm able to see kernel time in the process summary window. Hmmm... a thread that's in a busy loop, waiting on a flag that requires kernel privilege to read, "should" poll that flag at a low frequency -- I'd hope no more than once every ten seconds. Privilege-escalations and privilege de-escalations are expensive, and a dll with a polling loop running continuously at kernel privilege also seems a bad idea to me. Ideally this flag would be recoded as a semaphore-wait in the kernel with a callback hooked to its signal.... but that might require a major recoding of PhoneExperienceHost? Anyway I'll leave the diagnosis & repair to the Windows QA team! But... if I ever again have an overheating laptop from PhoneExperienceHost I'll take some screenshots from v17.02 Process Explorer, using the following as my baseline for a non-problematic PhoneExperienceHost:
PhoneExperienceHost.exe is a long way down the list of processes when I sort them by total context switches during the current session of Windows11:
Also when you close the app from taskbar, process not terminated (and when your PC go in idle, it will use CPU again) and you must start task manager to terminate process "PhoneExperienceHost.exe"
In Process Explorer you can see that thread named "dwmcorei.dll!LiftedCompositionEngine_Initialize" loads your CPU bug unfixed for months. The only solution is not to use Phone Experience.
