Laptop keeps shuting down when i run McAfee Quick or Full scan

[#1]

os Windows 7
500HDD (297GB free of 465GB)
Plusnet Protect
Use Firefox & Chrome
Developed a shutdown problem. Successfully detected and either deleted or quarantined Trojan, spyware/malware, and other viruses, so i backed up my important files to an external drive;
scanned that for any transferred virus: clear
=== Decided to go for an extreme clean install as Laptop over 6yrs+ old. Wanted to clear out any hidden folders once and for all ===
Used DBAN to completely clean-wipe my drive
Done a fresh install of of W7 Professional
reloaded my back-uped up files....
and  the prblem's come back with a real vengeance. Having to type this in "safe mode+networking".
Takes mupltiple start-ups to load any Windows Update, Plusnet Protect, any spyware checker, etc..
Becoming a real heachache  
!!! HELP !!!
How can i make "McAfee to run at boot-up"?
Doing anything in safe-mode is limited
and standard-mode i get shut down within two minutes of running anything new software or scanner

[#2]

McAfee = trouble. I got shot of it over a decade ago. Even on this PC and the netbook I uninstalled it immediately as it's so much trouble.
This sounds like an overheating problem though - you may need to get it dismantled and cleaned out (especially if you have pets / pet hair / dust where you use it). When it's dismantled the fan unit itself will need dismantling too and cleaning out. Many laptop repair folks will dismantle it, apply new thermal paste to the processor, put in a copper shim to conduct more heat etc but completely miss the dust thats clogged up the cooling fins inside the fan unit  
Here's one I dismantled last year - it doesn't look too bad here assembled:

Take it apart though and this is a common problem that many laptop repairers don't realist exist:

The dust is completely blocking the cooling fins - air is supposed to flow through there to cool down the metal fins which in turn cools the rest of the copper and lets it draw more heat off the processor. You can't normally see this dust from the outside either so any tech who claims "I checked it and it was fine" can't be 100% unless it's been dismantled.
You say your anti-virus is causing this. Your AV is going to be processor intensive and thus the processor will generate more heat. If the heat can not be drawn off by the copper heatsink and then exchanged via the cooling fins with cool air then it will essentially choke on heat and the motherboard will shut it down to protect itself.

[#3]

How easy is it to dismantle ?  is it just a couple of tiny screws holding the two outers together ? or more complicated than that?

[#4]

Not sure if thats aimed at me or the op but the few I've dismantled have been rather intricate.
Definitely not for those with a nervous disposition.

[#5]

Question was for you,.... but I just wanted to know..... YouTube shows using Compressed Air to clear the vents..... ( from inside and outside )

[#6]

Unless you dismantle the fan unit (btw I was speaking of the whole laptop) then compressed air won't clear the fan cooling fins because the dust will still be in there and simply blown back into the fins by the centrifugal force of the blades.
In the photo I posted, there is no way compressed air would have cleared that. I had to get a small brush to clear that lot out.
The owner was very pleased with the result too. It went from concorde grade sound to rather nice and quiet. It also turned on a lot less too. Youtube and various other sites for that model were all blaming the copper shim under the heatsink for being inadequate but nobody mentioned anything about the fan. It didn't really make sense.. a professional company like HP not knowing anything about their own heatsinks.. so I dismantled and lo and behold there was a carpet of dust in there.

[#7]

As above - I generally clear out my laptop heatsinks every 6 months or less.
You should also do a search for rootkit viruses as these can be very very stealthy - https://support.kaspersky.com/viruses/disinfection/5350

[#8]

Carpet of dust, you say, are you being generous
On a serious note we had a friend stay over just before xmas and she took her laptop to her sons mate to find out why it was overheating, the guy stripped it down and told her she needed a complete new fan that would cost over £70 including labour.
When she came down I asked her to bring it with her, and of course being a Dell it needed a complete strip down just to access the fan, when I seen the amount of Dust / Dog hairs etc  before I stripped the fan assembly to clear the crud.
I asked her why the guy didn't clean it out, she said she didn't know, she was also disgusted that her sons mate didn't clear the crud which was that bad that it stopped the fan from moving more the 2 - 3 mm yep that's 2 - 3 mm

[#9]

I often whip off the memory plates / fan cover etc on the back of the laptop and give some short sharp blows in through the exhaust port - not always the best solution but for buildup of fluff and dust usually suffices without too much of a stripdown.

[#10]

Depending on environment at least once a month with canned air should suffice.
With
cigarette smoke
Pet hairs,
crumbs from both adults & kids,
wooden flooring as brushing causes more flying dust,
auto plug in smelly  rubbish causes the flying dust to become damp and stick like brown stuff to a blanket,
using laptops on the lap or clothed surfaces
IE: Duvet covers without a board creates fibres off the clothes to get in the fan requires a more frequent blast of air perhaps weekly

[#11]

I gave my laptop a good clean out last year, had the fan apart & cleaned out the copper heat pipes.
Also cleaned of the old thermal paste from the processor & used some new paste on reassembly.
HP NC6000, I can take them apart with my eyes shut, don't even need to look at the service manual any more 

[#12]

Quote from: DomS

I often whip off the memory plates / fan cover etc on the back of the laptop and give some short sharp blows in through the exhaust port - not always the best solution but for buildup of fluff and dust usually suffices without too much of a stripdown.

That was exactly what I was talking about earlier:

Quote from: 7up

You can't normally see this dust from the outside either so any tech who claims "I checked it and it was fine" can't be 100% unless it's been dismantled.

Ultimately your idea may very well delay the build up but it's still going to happen eventually.

[#13]

Yes it does typically delay build up especially if the laptop in question had never been blasted before & where dust > hairs > smoke etc has already started to stick to the fins

[#14]

Quote from: 7up

.......This sounds like an overheating problem though - you may need to get it dismantled and cleaned out (especially if you have pets / pet hair / dust where you use it). When it's dismantled the fan unit itself will need dismantling too and cleaning out. Many laptop repair folks will dismantle it, apply new thermal paste to the processor, put in a copper shim to conduct more heat etc but completely miss the dust thats clogged up the cooling fins inside the fan unit   Here's one I dismantled last year - it doesn't look too bad here assembled: The dust is completely blocking the cooling fins - air is supposed to flow through there to cool down the metal fins which in turn cools the rest of the copper and lets it draw more heat off the processor. ....... You say your anti-virus is causing this. Your AV is going to be processor intensive and thus the processor will generate more heat. If the heat can not be drawn off by the copper heatsink and then exchanged via the cooling fins with cool air then it will essentially choke on heat and the motherboard will shut it down to protect itself.

Laptop: Acer Aspire 5315
Followed your advice and looking promising:
previously updated my cpu and put in a new hard-drive, so already familiar with internals of my laptop (thanks to YouTube) and thought while i was in there, why not have a look at the fan.... and was incredulous at the amount of gunge collected - as a have-a-go-but-non-techie, shocked me.
Just given it another look, and, you're right, full of fluff, etc....
Can actually hear the fan softly running now it's all cleaned out.....
.... and first time this laptop hasnt shut down in user-mode, while typing this, and running a deep virus scan.
MANY THANKS
If this forum allowed (y) thumbs ups i'd tick you!

[#15]

A reason i was concerned about not being able to fully run my Plusnet Protect, and asking how to run a virus program at Boot-up
is because i'm still experiencing what i call a computer-drag.
When i'm doing anything on the net, there's a delay to my typing and pages-load, and occasionally a screen flash.... making me fearful of something running in the back ground like a key-logger.....
or is it such programs as Ghostery, Disconnect and Adblock-Plus that could be interferring with my browser?
I can type fairly well so am looking at the screen as i type, and notice a few seconds delay before the screen-typing catches up?
Surface virus scans and programs like SpybotS&D havent high lighted anything, and my McAfee live-monitor is working as i occasionally see messages like "something tried to load to your computer and it has been blocked", or "virus detected and has been deleted/quarantined).... so i can see i have some semblence of protection.... but concerned about this screen drag.
Any ideas?
Cheers