Scenario: You have a new Snapdragon X Elite laptop. Malware hides a persistence entry via a custom ARM64 shell extension.
Recommendation: Use autoruns64a exclusively on ARM64 hosts. autoruns 64 vs autoruns 64a
The naming convention stems from Microsoft’s historical need to support multiple 64-bit platforms. In the Sysinternals suite, the "a" suffix explicitly denotes the "AMD64" processor architecture. Since AMD64 became the universal standard, the non-"a" version (Itanium) is now a ghost of computing history. Many users mistakenly believe the "a" stands for "administrator" or "advanced," but it is strictly an architectural marker. Scenario: You have a new Snapdragon X Elite laptop
We tested both versions on three systems: Autoruns 64a :
| System | Architecture | Test | Result |
| :--- | :--- | :--- | :--- |
| Dell XPS 13 (Intel i7) | x64 | autoruns64a.exe | Fails to launch (invalid architecture) |
| Dell XPS 13 (Intel i7) | x64 | autoruns64.exe | Works perfectly. Detected 342 startup entries in 8 seconds. |
| Surface Pro X (SQ2) | ARM64 | autoruns64.exe | Works via emulation. 323 entries in 22 seconds. (High CPU usage) |
| Surface Pro X (SQ2) | ARM64 | autoruns64a.exe | Works natively. 323 entries in 4 seconds. (Low CPU usage) |
| MacBook Pro M3 (Parallels Win11) | ARM64 VM | autoruns64a.exe | Works natively. Detected ARM64 hypervisor drivers correctly. |
Key Takeaway: No functional difference in detection count on standard machines, but massive performance gap on ARM64.
Autoruns 64a: