AutoIt Error Line -1: Variable used without being declared

You got this message on Windows startup. What is it?

The message is related either to a corrupted/damaged AutoIt script of a new installed software/s or an error from a virus/malware created using AutoIt script. In this article, the error was came from a virus/malware broken script.

How to begin?

Note: Please read carefully.

Download Trend Micro HijackThis 2.0.2 to your desktop. Double click on HJTInstall.exe, it will prompt you to extract hijackthis.exe to C:\Program Files\Trend Micro\HijackThis. When the install is complete, HijackThis will automatically launch. When the license agreement appears, select "I Accept" and then click on the "Do a system scan only" button. Wait until the scan is finished.

What next?

Find the following entry in HijackThis scan result:

O4 - Global Startup: windows_system_32-dll.exe

windows_system_32-dll.exe was registered as a "Trojan.Agent/Gen".

How to remove it?Tick the checkbox left to the entry and click "Fix checked". Exit HijackThis.
This should fix the error.