This one has been bugging me for a while. Apologies for the long story, I've tried to add as much as I can. Perhaps someone recognises this.
The problem:I'm using Win10 on a Dell domain laptop at home (i7, 32GB), and regularly explorer.exe starts using excessive CPU time (up to 40%), slowing the laptop down severely (and additionally causing the CPU fan to run at a very noisy max speed). This happens when I have a lot of explorer windows open (say, 10+). I've opened many more windows without issue on previous devices (Win10/7/XP), so I'm not quite sure why this suddenly is a problem. It goes away when I close the majority of the windows (sometimes I include a complementary reboot).
Not sure if this is related (if definitely not I'll start a separate question), but PgUp and PgDn on the keyboard regularly refuse to operate. If this happens, I have to press them down for a number of seconds for them to spring back into action, after which they work as intended again.
Attempted fixes:So far I've ran SFC /scanall, to no avail, and checked both file system and hardware integrity of the attached drives (1x SATA M2, 2x 2.5" USB HDD), as well as done a memory scan through Dell diagnostics. The latter more to rule it out, than me suspecting memory is the root cause btw. All drivers appear to be the latest, windows updates are automatically applied when released.
As I've had USB power issues with a previous laptop, I was suspecting perhaps problems with too much power being drawn. Connecting my Android phone to an USB3 port for charging also regularly (but not always) induces high CPU usage of explorer.exe. I've therefore tried an old 180W adapter instead of the 130W one that came with the docking station, and I get the impression this has slightly reduced the occurrence of the above, but not by much. I'm also not sure if this could be an issue in the first place, as most of the open explorer windows tend to be on the on-board M2 drive (and not the attached HDDs).
Possibly relevant (by association):4x disconnected CIFS shares and 4x webdrive shares, VPN intermittently used (when required for work services), HDMI 3.1 cable connected to 4K TV from docking station (used as an extended desktop). Work dir on M2 drive is permanently SUBST'ed as the D-drive. Two Logitech dongles are permanently attached (KB and mouse). WiFi AP is 1m away from device, connection is very stable.
tl;dr: what could cause explorer.exe to claim a lot of CPU time over extended periods?
20 Reset to default
