I have a Haeir Laptop from Oct 2014 with OEM Windows 8.1 on it.
Lately (last 18 months), my laptop has been on high CPU usage quite a lot more than usual.
From the task manager and Services tab, I have found out Windows Update is the bad guy.
If I stop the "wuauserv" service, the CPU usage comes back to normal.
But whenever I try to install a Windows update, or try to update antivirus (Windows Defender) definitions, or try to update any driver from the Device Manager, it starts again. I give it time to do whatever it is trying to do but it continues on for weeks without completing, until I have to stop it myself for some reason. I usually sleep my computer or hibernate it, so it continues whatever it is doing after I wake it up every time.
I know some things about computer security so I never click on phishing links etc. and never run any software from internet unless I am sure of what I am doing. The Windows Defender somehow keeps up to date and is always on the watch. It has caught scripts and viruses from USBs a few times so it is probably doing its job fine. I am almost sure that my PC is clean from malicious software.
I usually mind my own business and don't try to tell Windows how to do its job, but this problem is getting on my nerves lately for the following reason. I want to help my Windows get out of it.
1) It is ruining the battery. The original battery wore out soon with constant 50% CPU usage. It discharged within 1.5-2 hours without the cahrger, so it came through 2-3 charge discharge cycles every day. I replaced the battery. The new battery lasted even less with the high CPU usage and went through 3-4 charge discharge cycles everyday. Didn't last more than 8 months until its backup went less than 10 minutes.
2) I can't get any Windows updates. I have set the update setting to manual. So whenever I try to update it, it goes into some deep thinking and continues thinking for the next 20-30 days until I have to interrupt it for some reason by stopping the wuauserv.
3) I can't install any new drivers (I work on Arduino and other hardware, so I need it a lot). Whenever ask it to search and install the drivers automatically, it goes into CPU usage and keeps in some deep thinking until I have to kill the update process.
One thing I would like add. A few years earlier, it had started exhibiting this behavior, but it wasn't so toxic then. It used to go into high CPU usage, but recovered in a few hours and it had completed whatever task it was trying to do (Windows update, install driver, every time on start up). But the time kept getting longer until now I let it do this thing for 40-50 days but it doesn't stop.
Otherwise the computer is perfectly fine. I have some mildly heavy software on it and the hard disk is about 80% full, but it doesn't mind them much. It comes to desktop in 30-40 seconds of pressing the stat button and can open Excel in the next 5-10 seconds.
Please advise me on how to help my Windows get out of its misery.