Irql_gt_zero_at_system_service

The latest BSOD on my PC is IRQL_GT_ZERO_AT_SYSTEM_SERVICE.

What action should I take to remedy this, please?

Please remove / disable items from the startup in taskmanager
These programs could interfere with the boot process giving you trouble and increase the boot time.

Uninstall Avast while troubleshooting
Avast - Uninstall Completely - Windows 7 Help Forums

Code:

*** WARNING: Unable to verify timestamp for aswStm.sys
*** ERROR: Module load completed but symbols could not be loaded for aswStm.sys

Check your protection software for software updates, they are the most popular with network related crashes.

Code:

Probably caused by : NETIO.SYS

Also check your network drivers for updates
Driver Reference Table - netr28x.sys
Driver Reference Table - rt640x64.sys

Let me know how it goes :)

Thank you very much for your help.

The link to the driver reference table rt640x64.sys takes me to RealTek where I have downloaded and run the program to install a new driver. So far, so good.

The first link to netr28x.sys sends me towards a MediaTek page which no longer exists. I have, however, navigated to
Downloads - Drivers and Firmware - MediaTek
and downloaded the top link, which seems relevant. When I try to run this program, I get an error message
Attachment 50600
Windows help is a bit confusing as to how to allow this file to run. Internet help suggests using Internet Explorer to allow this (I don't use Internet Explorer - I'm a Firefox man), so I've tried this, only to discover a veritable lexicon of publishers, none of which seems to be MediaTek, unless they publish under an esoteric cognomen.
What now, please?

Right click the file and choose properties.
Does the properties say it is being blocked?
If it does, unblock it and try to run it.

Thanks for getting back to me.

I've tried that: it was blocked, so I unblocked it.

Running it results in this error message:
Attachment 50608
This is particularly annoying, in that I am the administrator! Even if I select "Run as administrator" I get the same error.

I've tried shouting at the CPU, but this didn't work either! What next, please?

Scan the file in VirusTotal, User Account Control (UAC) is blocking it because it thinks this file is unsafe.
VirusTotal - Free Online Virus, Malware and URL Scanner

When the result is good, change temporary the UAC settings to run the file.
User Account Control (UAC) - Change Settings in Windows 10 - Windows 10 Forums

Thank you again.

The file passes the online scan.

I've changed the user account settings to "never notify me".

I still get the same error message.

This is very tiresome.

The same from UAC?
Look in the title of the message to see where it is coming from.

Sorry, I don't understand what you want me to do.

Is this message from User Account Control?