After updating Avast Free I get a BSOD after some idle time. It seems that Avast is trying to scan for viruses and uses ngvss.sys. It seems to be a relatively common problem after updating avast (found many topics outside this Avast forum) but no solution: people recommend not to use Avast and use an other combination. I want to stay with Avast, but I also can´t find any solution. The testsystem runs on windows vista 32 bits sp2.
Error STOP: 0x0000008E
ngvss.sys address 88962DC1
Follow instructions: https://www.avast.com/faq.php?article=AVKB33#artTitle
Hi
I am also having blue screens on the same type of system, Vista 32 bit. The link given above to file a report seems to be for paid version of Avast only. I am using the free version. Can anyone tell me what to do about this?
I ran Windows Debugger on 5 dump files, 3 results are as follows (extracted info):
kernel mode exception not handled 10000008e
default bucket id Vista driver fault
process name system
module name ngvss
image name ngvss.sys
2 dump files gave this info:
kernel mode exception not handled 10000008e
default bucket id common_system_fault
process name system
module name ngvss
image name ngvss.sys
Google search says ngvss.sys is an Avast driver
Dell site said the ‘image name’ info is almost always the file causing the blue screen
thanks
Liz
I have
Avast free prog. version 11.1.2241
windows defender is also running, (I think defender has always been running) no other security related software
have always used Avast on that machine from the beginning
thanks
Does the system support hardware virtualization and if so, is it enabled or disabled in the bios ?
sorry, don’t really know what hardware virtualization is, or where to look for it in the BIOS
The motherboard manual will tell you where to look.
Or simply enter the bios and look around.
couldn’t find anything in the BIOS about virtualization
I downloaded Speccy which shows everything on your computer
it says, under the processor, next to virtualization ‘not supported’
What is the make/model of the motherboard ?
If you don’t know this tool can tell you :
http://www.ache.nl/cgi-bin/download.pl?file=everesthome220.exe
motherboard Dell Inc. 0RY007 (Socket 775)
just had another blue screen, happened after I had ‘safely removed’ a thumb drive. When I pulled the drive out, blue screen. This happened, if I’m not mistaken, when I pulled out my passport ext. hard drive and got one of the earlier blue screens.
This last blue screen dump files shows all the same info as the first I gave above (the one with the vista driver mentioned)
In addition at the bottom of the analysis it said:
WARNING: unable to verify time stamp for ambakdrv.sys
ERROR: module load completed but symbols could not be looked up for ambakdrv.sys
Probably caused by ngvss+(e9b2)
Motherboard manual > http://www.dell.com/support/home/us/en/19/Products/?app=manuals
I just got the below info from Speccy–maybe it will give you what you’re asking for?
If not, could you tell me why I need to see the manual, and what I would be looking for, and what it might have to do with the Avast driver? (I feel like I’m being led around a little blind, lol)
Motherboard
Manufacturer Dell Inc.
Model 0RY007 (Socket 775)
Chipset Vendor Intel
Chipset Model P35/G33/G31
Chipset Revision A2
Southbridge Vendor Intel
Southbridge Model 82801IR (ICH9R)
Southbridge Revision 02
System Temperature 40 °C
BIOS
Brand Dell Inc.
Version 1.0.12
Date 3/1/2008
Voltage
CPU CORE 1.152 V
MEMORY CONTROLLER 3.040 V
+3.3V 3.312 V
+5V 5.053 V
+12V 12.032 V
+5V HIGH THRESHOLD 5.000 V
CMOS BATTERY 3.024 V
PCI Data
Slot PCI
Slot Type PCI
Slot Usage In Use
Bus Width 32 bit
Slot Designation PCI1
Characteristics 5V, PME
Slot Number 0
Slot PCI
Slot Type PCI
Slot Usage In Use
Bus Width 32 bit
Slot Designation PCI2
Characteristics 5V, PME
Slot Number 1
Slot PCI
Slot Type PCI
Slot Usage Available
Data lanes x16
Slot Designation PCI3
Characteristics 5V, PME
Slot Number 2
Slot PCI
Slot Type PCI
Slot Usage Available
Data lanes x1
Slot Designation PCI4
Characteristics 5V, PME
Slot Number 3
PS: I don’t believe there is a separate manual for the motherboard. All Dell offers there is the manual for the computer, and it does not give details on the motherboard.
I googled and couldn’t find a manual for the motherboard either. 
Can anyone tell me if this Avast driver that is causing my problem ngvss.sys will be deleted if I use the Avast removal tool to remove the whole program?
Looks like this may be the only way to get this solved (without spending half my life on it, at least, lol)
control panel/programs and features/avast/change.
Deselect the NG component.
THANK YOU! I think 
Will have to wait a while to make sure there are no more blue screens.
I had a little problem with this, so in case any others read this, I will fill in some details.
After doing what you said above, a screen comes up with options update, repair or modify. I clicked on ‘modify’ and it gives a long list of components of Avast asking what you want to INSTALL, with everything checked. Underneath it says ‘change’ and I clicked that because I thought it would give options to UNINSTALL. Also NG was not on the list.
No, it just installed everything, lol. Eventually I went back to the install list and figured out that NG is listed under “Secure Virtual Machine” (thanks to some of the looking I did for Eddy) so I unclicked that one as you said, and clicked ‘change’ again which installed everything except NG. I could see that it removed the driver that was hopefully causing all the problems.
And now I don’t have to uninstall all of Avast!
I tested by plugging in my thumb drive again. Then I did the safe remove and unplugged the thumb drive. Twice before when I did that I got blue screens involving this driver. This time it did not blue screen. I tried it again and it did not blue screen again.
Yay ! but will need to wait and see to make sure this is a final fix, as had random blue screens at other times. But I do think it must be fixed, esp since I saw that driver come off my machine.
So, thank you, thank you, thank you Davexnet. :-*
You’re welcome. I don’t know if you originally did a custom install and selected the NG component, or whether you did the basic install
and this component is just bundled along with it. I’m a user like you, but from what I’ve seen, this “secure virtual machine” is more like some
nutty professors science experiment rather that a reliable, useful piece of software. I have to question the install by default of this component.
I believe I just let Avast update itself when it told me an update was available. I just assumed Avast knew what it was doing.
From what I understand from the help I got before you, the NG feature has to do with hardware virtualization, and I could be wrong, but I think that if your motherboard/processor supports this, you can then create ‘virtual machines’ on one computer. Leo (at AskLeo) has multiple versions of Windows on one computer so he can answer questions about all the versions. I had wanted to put Win 10 in a virtual machine on my newest computer so I could play around with it, but I think that’s above my tech level at present. So I guess having protection for virtual machines is actually a good idea, in theory maybe
Anyway, my older computer apparently does not support hardware virtualization (I assume yours does not either) and thus the NG problem. That machine is a 2007 Dell, with Vista still supported, so seems Avast would know not to install NG…but ‘nobody’s perfect’ ???
Anyway, without your help I would have already uninstalled Avast and installed another antivirus program, which I am glad I did not have to do. I have used Avast for many years and it has served me very well, except for once I decided to upgrade to the paid version, out of gratitude for all the free time, but Avast developed a problem, and after the year was up I went back to the free version, problem gone. So I’m still on ‘free.’
Thanks again so much, Davexnet, I had just about given up on ever fixing this and not looking forward to the hassle of getting a new av program! 
PS: I just looked on my newer machine and I have the NG virtual machine thingie installed, and Avast is doing ok so far.