Hi Adrian
As you probably know, you can wake your system from sleep using your mouse movement or keyboard.
Allowing your mouse to wake the computer is touchy as even a slight bump to your desktop will do it.
Certain services will do this too including MS update and they can be disabled.
You can prevent your Network card doing this in Device Manager.
Expand the list for “Network adapters”
Right-click the adapter to be configured and choose “Properties”. There may be several adapters, one for Ethernet, one for wireless, and others like Bluetooth.
In the dialog box that opens, click the tab “Power Management”
Uncheck the box “Allow this device to wake the computer”
Click “OK” and close up Device Manager.
You can determine what service or device woke the computer last with the following command in an elevated command prompt.
powercfg –lastwake
To find out which devices are enabled to wake up the PC, enter this command:
powercfg -devicequery wake_armed