Hi,
If the uninstall utility and other methods don't work, I suggest trying the methods below.
1) Please try deleting all Avast Antivirus files from your computer. You can do this by launching Windows Explorer, and going to the path
C:\Program Files\Avast Software and deletung everything in it. You will also have to delete
C:\Program Files\Common Files\Avast Software as well.
2) You could try using Safe Mode with Networking. To do this, you must follow the steps here:
https://www.lifewire.com/how-to-start-windows-xp-in-safe-mode-2624542. If you are done with entering safe mode, see if you can use the internet to search.
3) If you have made a system restore point before, you could try restoring your system to that state.
4) You can kill the setup process, since it is currently running. You might also want to disable its startup application host, too. To open task manager in XP, right click the taskbar and select
Task manager. If you do not see this screen, then you can also use the keyboard shortcut, which is
Ctrl + Alt + Del. Then, try to kill the process of the setup system, and uninstall Avast using the uninstall utility.
5) Try the uninstall utility again, but in Safe Mode. It requires Safe Mode to be able to delete all Avast files from your computer.
6) Avast has ended support for Avast on Windows XP, now the last version available on XP is very low in quality. I strongly recommend updating to the latest Windows version. His vould fix the "Incorrect Win32" issue, as Windows XP and Windows 10 might use different exe formats. This is the best expected issue. If you are still having trouble, remove your drive from your XP, put it in a Windows 10-installed device, then run the Avast Uninstall Utility.
7) You can repair Avast in Settings. If Avast cannot open, you could try downloading Avast Free Antivirus source code files, and moving them into the default Avast installation directory.
If this helped or worked, let me know!