svchost oddness

[#1]

Not continuous problem, just occasionally, but can't pin it down.
Discovered this because items on the desk next to the laptop were hot when I picked them up!
PC laptop (Win7) sitting idle most of evening. No disk activity. Nothing running.
But belting out heat from the fan.
Check resource manager -- svchost.exe (netsvcs) using 50-60% continuously.
Unplug from internet. Check all over for something running. Everything else appears to be normal, and idle.
Restart.
And drops back to the normal 3% idling. And stayed that way. (Until the next time...)
What's svchost is up to? Can I drill down and find out exactly what its doing?
Noticed it about 4 times over past couple of months. Can't seem to equate it with any particular activity.
Was suspecting MS updates, but I haven't had an update for months - since i hid the v10 offer to upgrade. And no sign of update activity on task manager.
btw. Don't use machine for much. Its the 'pick-up emails and write letters' PC. Nothing heavy. Basic OS and MSOffice(7). Use Thunderbird and Firefox.
Do have AVG (not doing anything when I checked), Malwarebytes, and SpyBot.
Don't like it overheating like that  

[#2]

have you made sure your business setting is switched off to ensure your pc isn't acting as an auto proxy for someone when your not using it ?

I have been caught out by that a few times in the past
one other consideration is that you might of inadvertently co-opted the system to a social bot net (genome project or similar) or been inadvertanly co-opted into a not so social one /

[#3]

Not that I'm aware of. I'd see network activity if so?
It appears to be doing absolutely nothing!
Seems to be a growing problem now, tho. Is 50-60% normal for just sitting idle online?
PC getting very hot as soon as its online.
Suspended svchost (netsvcs) for a while and dropped to usual 5% and cooled off. Resumed and back to 60% and overheating...
Coincides with installing Adobe Reader... Could it be?
(I'll try uninstalling that -- don't like the damn program anyway...)
Otherwise, I'm at a loss.
PC is currently cooking....

[#4]

You could try Process Explorer, although it may still show several services under one svchost.exe process.
I think Windows events log record when each service starts and stops, which might help.
If have haven't had any updates for months, maybe that's something that needs fixing.

[#5]

Thanks, ejs. Just downloaded Process Explorer, will give that a go later.
Seems I was wrong about it being only online -- it happens if unplugged from network as well. Takes few mins to start whatever it starts.
Be interesting to see when/what actually starts.
Event logs not showing anything critical or warning over past 7 days.
Yes, need to sort out the updates thing.
(That was odd. Got the v10 icon and accidentally clicked it one time. Got the message that Win 10 cannot be installed on this computer. Yay! And then offered me a link to buy a new computer!!! Ha!
But haven't had an update notification since then. Related to this? No idea.
This is an old Dell inspiron 1720 from Vista days with Win 7 on it. Use it as a desktop.  Wonder if its struggling a bit? But its been fine for a year or so of very moderate use. Best PC I've ever had.)

[#6]

I know I'm repeating same issue over two threads here but figured I'd update this one as its an issue on MS communities as well (no answers), in case anyone arrives at this issue the same way I did.
My problem was Windows Updates.
Have non-stop wuauserv service problem. Now seriously overheating.
Just need to quit checking for updates. And figure out how to stop Windows Updates from permanently running (round in circles). Its completely broke!
BTW - important --
Don't try to do a system restore to mend busted updates. It renders WU into permanent confusion. (This from MS techie on MS communities.) Uninstall updates first, re-boot, then do system restore... Assuming you know which ones are broke...
This can apply to folks who've got borked Win 10 installations as well.

[#7]

Perhaps my also Vista era laptop has an underpowered CPU, or an adequate cooling fan, but I can run both CPU cores at 100% continuously, of course it gets hot, but I wouldn't say it overheats. The CPU fan at the lowest speed is usually capable of maintaining the temperature such that the fan doesn't have to go any faster. If it gets hot enough for the CPU fan speed to go above its lowest speed, that means it's time for me to switch it off, turn it upside down and blow the dust out. Considering it's almost 7 years old and still working, it doesn't seem to have done it any harm.

[#8]

But still don't want wuauserv chasing its tail on a permanent basis!
(When I temporarily suspended wuauserv yesterday the machine was running waaaay faster.)
WU presumably saves downloaded updates to a file to install from - yesterday I had no updates to install. Now there are 41 although there's been no update connection - so, internal issues here.
Twice I've had 'installing updates' on shutdown, even tho it has shown 'failed' on installed updates page.
Its seriously screwed up. I'm just wondering if I keep doing this it might finally resolve its own internal issues... (Need fingers-crossed emoji here.)
'Checking for updates' is still just hanging forever (and not making external connection) if you try that.
See MS Communities. Something is up with Win7 updates. (And many after failed Win 10 upgrades, like me.)
I've been right-clicking on failed updates and follow thru to 'what to do if it goes wrong' there's a fix you can run which will oftentimes tell you some things were fixed. This seems to jog it along a bit. (This isn't the same as the 'fix it' man, btw, which does nothing - in my case.) Though you may not realise its worked until you shutdown...
Anyway... such fun...

[#9]

I have seen this problem (wuauserv runs amok) on Windows XP and there was a documented fix, as far as I can remember.  But if updates fail consistently you need to intervene to fix the problem. 

[#10]

After my last post I just shutdown.
Startup about an hour ago WU still showing 41 updates to do.
Just clicked install again - out of monotony more than anything. Ethernet not even plugged in.
Whaddya know -- its starts updating. 39 done, 2 failed.
Restart. Two more to do. Click. Done.
No clear idea what happened, why, or if it was something I did.
During the course of this (since Thursday) used the 'fix' about 5 or 6 times. 4 of those fixed something. 2 just hung.
It involved watching the disk thrashing about for ages on resource monitor quite a bit.
So, no answers unfortunately, except keep hammering away at it, lots of restarts, and WU seems to get there in the end.
Obvs not just one process at work here. Distinct impression one hand didn't know what the other was doing. And several hands. (And that's WU, not me. Though I had no idea what I was doing either!)
However. wuauserv has now gone home, at last, and computer running cool again.
Relief.
Thanks all for suggestions 
Fingers crossed
@ejs -- amazing thing about this old Dell is that despite being aged it runs cool usually. More so than any other laptop I've had. Not that it gets hammered or anything...
Did have a thorough good refurb last year. Not sure what the guy did to it.