Daemon Tools Sign Check Error Guide

Once you fix the Daemon Tools sign check error, you want it to stay fixed.

The "Sign Check Error" is a proprietary security mechanism built into modern versions of Daemon Tools (specifically versions after 2015, including DT Lite 10 and 11). When Daemon Tools launches, it checks the digital signature and integrity of its own core drivers (specifically dtsoftbus01.sys or dtlitescsibus.sys).

If the signature is missing, corrupted, or fails to validate, the software assumes the drivers have been tampered with—either by malware, a failed update, or an overzealous antivirus. Consequently, it refuses to mount images (ISO, MDX, MDS/MDF) and shuts down with the sign check error.

The Daemon Tools sign check error (0x20000 and similar variants) is almost always a clash between an old driver signature and modern Windows security protocols like Secure Boot and DSE. daemon tools sign check error

The fastest solution is Disabling Driver Signature Enforcement (Method 1) for a quick fix. The most permanent solution is Disabling Secure Boot (Method 4) combined with the Official Signature Patch (Method 5).

However, if you are a casual user who only needs to mount ISO files, save yourself the headache. Use Windows’ native mounting tool or switch to WinCDEmu.

For power users who need virtual drives for old games (SecuROM/SafeDisc), the extra effort of debugging Daemon Tools is worth it—just follow the nine methods above in order, and you will have your virtual drive back in under 20 minutes. Once you fix the Daemon Tools sign check

Still stuck? Post your exact error code (e.g., 0x20000, 0xE000024B) in the comments below or visit the official DT Soft forum. Do not download "sign check fixers" from random websites—they are almost always malware.

Last updated: October 2025. Tested on Windows 11 Pro (23H2 & 24H2) and Windows 10 (22H2).

Sign check error in Daemon Tools occurs when the application detects a problem verifying the digital signature of a file, driver, or module. This prevents the software from loading unsigned or tampered components, and is a security measure enforced by Windows driver-signing and code-signing policies. The "Sign Check Error" is a proprietary security

Running bcdedit /set testsigning on lowers the security posture of your operating system by allowing unverified drivers to load. It is recommended to run this only when necessary (e.g., using Daemon Tools) and use the Revert (Option 3) feature when you are done using the software, if possible.

This is a common issue, typically arising when you try to install or run Daemon Tools (especially older versions like Daemon Tools Lite) on newer versions of Windows 10 or Windows 11.

The error usually appears as a pop-up stating something like "Sign check error" or "Digital signature is missing or corrupt."

Here is a solid guide on why this happens and how to fix it.