The primary difference between Autoruns64.exe and Autoruns64a.exe is the CPU architecture they are designed to run on. Both are 64-bit versions of the Sysinternals Autoruns utility, but they target different hardware. Comparison Table: Autoruns64 vs. Autoruns64a Autoruns64.exe Autoruns64a.exe Architecture x64 (64-bit Intel/AMD) ARM64 (64-bit ARM) Typical Device Standard Desktops & Laptops Surface Pro (ARM), Snapdragon PCs Failure Mode Won't run on ARM-only systems. Errors as "not a valid Win32 application" on Intel/AMD. Detailed Breakdown
Autoruns64.exe: This is the standard 64-bit version used by the vast majority of Windows users. It is optimized for 64-bit Intel and AMD processors. If you are using a typical desktop or laptop running 64-bit Windows, this is the version you should execute for native performance.
Autoruns64a.exe: The "a" suffix stands for ARM. This version is specifically compiled for ARM64 architecture, such as that found in newer "Always Connected" PCs or tablets like certain Microsoft Surface models. It will not run on standard x64 Intel/AMD systems and will likely trigger an error message if you try. Core Functionality Shared by Both
Regardless of the version you choose, the tool's core purpose remains the same: it provides a comprehensive view of all programs, services, and drivers configured to start automatically on your system.
Detection: Identifies startup items in the registry, scheduled tasks, and boot execution keys.
Security: Integrates with VirusTotal to check file hashes against known malware signatures.
Categorization: Organizes startup entries into logical tabs like "Logon," "Services," "Drivers," and "Scheduled Tasks" for easier navigation.
Actionability: Allows users to disable (uncheck) or delete entries to optimize system performance or remove unwanted software. Which one should you use?
For a standard Windows 10 or 11 installation on an Intel or AMD processor, you should use Autoruns64.exe. If you happen to run the basic autoruns.exe (the 32-bit version) on a 64-bit system, it is designed to detect the architecture and automatically launch the 64-bit version for you.
If you tell me what kind of processor or device you are using (e.g., a standard laptop, a Surface Pro, or a custom PC), I can confirm exactly which executable is right for your system. autoruns 64 vs autoruns 64a
Which Autoruns executable for AMD Radeon 64-bit? - Microsoft Learn
When you download the Sysinternals Autoruns package, you’ll notice several different executable files. Choosing between Autoruns64.exe and Autoruns64a.exe depends entirely on your computer's processor architecture. Quick Comparison: Which One Should You Run? Executable Architecture Autoruns64.exe x64 (AMD64/Intel 64) Most modern desktop and laptop PCs. Autoruns64a.exe ARM64
Devices with ARM processors, like the Microsoft Surface Pro (ARM) or certain tablets. Understanding Autoruns64.exe
Autoruns64.exe is the standard version designed for the x64 architecture, which powers the vast majority of Windows computers using Intel or AMD processors.
Native Performance: Because it is compiled specifically for 64-bit Intel/AMD systems, it runs natively without needing any emulation.
Comprehensive Scanning: It has full access to the 64-bit areas of the Windows Registry and system files, which is critical for identifying malware that hides in 64-bit specific "Auto-start Extensibility Points" (ASEPs).
Usage Case: If you are on a standard 64-bit Windows PC, this is the version you should use. Understanding Autoruns64a.exe
The "a" in Autoruns64a.exe stands for ARM. This version is built specifically for devices running on ARM64 processors.
ARM-Native: While ARM-based Windows devices can often emulate x86 or x64 software, running the native ARM version is more efficient and ensures the tool correctly reads architecture-specific startup locations. The primary difference between Autoruns64
Common Devices: You would use this on hardware like the Surface Pro 9 (5G), Lenovo ThinkPad X13s, or other laptops featuring Qualcomm Snapdragon processors.
Error Prevention: If you try to run the "a" version on a standard Intel or AMD machine, it will likely fail with a "Not a valid Win32 application" error. What About Autoruns.exe (The Standard Version)? The standard Autoruns.exe is the original 32-bit binary.
Self-Detection: Interestingly, if you run the 32-bit autoruns.exe on a 64-bit system, it is designed to detect your architecture and can automatically launch the 64-bit version for you.
Compatibility: It remains in the package primarily to support older 32-bit versions of Windows or minimal environments where 64-bit support is absent. Which autoruns executable to use? - Microsoft Q&A
Autoruns is a utility developed by Sysinternals that provides detailed information about the programs and services that are set to run automatically on a Windows system. The utility comes in two versions for 64-bit systems: autoruns64 and autoruns64a. The primary difference between these two versions lies in how they display and handle registry entries and file paths.
Autoruns64: This is the standard version of Autoruns for 64-bit systems. It displays registry entries and file paths in their native format.
Autoruns64a: This version of Autoruns is similar to autoruns64, but it has an additional feature. The "a" in autoruns64a stands for "alternate," and this version displays registry entries and file paths with their Wow6432Node redirected view. This essentially means that if you're looking at a 32-bit application running on a 64-bit system (which is common), autoruns64a will show you the registry entries as they appear to the 32-bit application.
The key informative feature here is that autoruns64a helps in troubleshooting and understanding the interaction between 32-bit applications and the Windows registry on a 64-bit system. On 64-bit versions of Windows, 32-bit applications that access the registry are redirected to use the Wow6432Node. This means that instead of writing to HKEY_LOCAL_MACHINE\SOFTWARE\YourApp, they write to HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\YourApp.
Using autoruns64a allows you to see these redirected paths, which can be crucial for: Autoruns64 : This is the standard version of
In summary, if you're working with 32-bit applications on a 64-bit system and need to understand or troubleshoot their registry interactions, autoruns64a provides a more accurate view of their registry activity. For general use or when working primarily with 64-bit applications, autoruns64 is sufficient.
Autoruns 64a, on the other hand, is an alternate version of Autoruns 64. The "a" likely stands for "alternate" or could imply a specific variant designed with additional features or for specific use cases. However, detailed public documentation on significant functional differences between Autoruns 64 and Autoruns 64a is sparse. Generally, the core functionality of Autoruns 64a would be expected to mirror that of Autoruns 64, with possible enhancements or targeted optimizations.
This is the million-dollar question. For 99% of standard malware hunting and startup management, both autoruns64.exe and autoruns64a.exe produce identical output when run on the same machine.
However, there are edge cases:
Arm64 Native Auto-start Locations:
Windows on ARM has introduced a few new ASEPs specific to ARM64 ecosystem components (e.g., certain type of scheduled tasks for ARM64-optimized background apps). An emulated x64 Autoruns might not enumerate these correctly because the COM object interfaces for those tasks may not be fully emulated.
ARM64 Kernel Drivers:
Malware authors have begun writing native ARM64 rootkits for Windows on ARM. autoruns64a.exe has native access to query the ARM64 kernel driver list via the ZwQuerySystemInformation syscall. Under emulation, autoruns64.exe relies on thunking layers that could theoretically miss a driver that only registers itself with the ARM64 kernel subsystem.
Timing-Based Anti-Emulation Malware:
Some sophisticated malware checks if it is running under emulation by measuring instruction execution latency (RDTSC/RDTSCP differences). If you run autoruns64.exe on ARM64, the emulation layer changes timing. Malware that detects emulation might hide its startup entries. autoruns64a.exe avoids this detection.
Verdict: For standard enterprise IT and most malware analysis, results are functionally identical. For incident response on ARM64 devices, always use autoruns64a.exe to be forensically sound.
Tool: Microsoft Sysinternals Autoruns v14.09
Builds compared: autoruns64.exe (x64) vs. autoruns64a.exe (ARM64)
Reviewed on: Windows 11 Pro (x64) & Windows 11 on Snapdragon (ARM64)
| Build | x64 PCs | ARM64 PCs | Forensic value | Speed | |-------|---------|-----------|----------------|-------| | autoruns64 | ★★★★★ | ★★★☆☆ (emulated) | ★★★★★ | ★★★★★ (x64) / ★★★☆☆ (ARM64) | | autoruns64a | ❌ Doesn’t run | ★★★★★ | ★★★★★ | ★★★★★ (native ARM64) |