I assume that you have x64 edition of Vista…
It seems that this issue is related to protection programs if the stack list is related to Windows Defener and AVG.
You should only use one protection provider per platform. Using multiple increases workload and can cause confusion between each other. Most 3<sup>rd</sup> party anti-virus programs
turns off windows defender when 3<sup>rd</sup> party provider is installed, or at least my McAfee does it. If AVG doesn’t do it, you should disable Windows Defener in Control Panel.
Begin of my x64 vista edition journey I had a lot of problems with McAfee Virus Protection until they made the x64 engine working correctly. I often encountered wired errors while installing or
using the software on x64 edition with McAfee. As I also have x32 environment I often saw that the error was only encountered in x64 edition and stack was always pointing to McAfee.
Anyhow, my recommendation is that you first install your antivirus program again, check AVG if they have any updates for x64 edition available, and then turn off Windows Defender.
If this does not help you need to raise a support request and follow the support guidelines of your anti-virus provider.
Let me know if disabling the Windows Defender solved the problem.