What is AsIO?

AsIO.sys is a Windows driver. A driver is a small software program that allows your computer to communicate with hardware or connected devices. This means that a driver has direct access to the internals of the operating system, hardware etc. The free file information forum can help you determine if AsIO.sys is a Windows system file or if it belongs to an application that you can trust.

Run a free scan to check for AsIO drivers in need of updating

AsIO.sys file information

The process known as AsIO belongs to software AsIO by ASUSTeK Computer (

Description: AsIO.sys is not essential for the Windows OS and causes relatively few problems. AsIO.sys is located in the C:\Windows\System32\drivers folder. Known file sizes on Windows 10/8/7/XP are 5,685 bytes (35% of all occurrences), 4,962 bytes and 6 more variants. 
The driver can be started or stopped from Services in the Control Panel or by other programs. The AsIO.sys file is a file with no information about its developer. The program is not visible. There is no detailed description of this service. It is not a Windows system file. AsIO.sys appears to be a compressed file. Therefore the technical security rating is 45% dangerous, however you should also read the user reviews.

Recommended: Identify AsIO.sys related errors

If AsIO.sys is located in a subfolder of C:\Windows, the security rating is 31% dangerous. The file size is 13,440 bytes (48% of all occurrences), 15,232 bytes, 13,368 bytes or 14,392 bytes. There is no description of the program. The program is not visible. The file has a digital signature. The service has no detailed description. AsIO.sys is not a Windows core file. AsIO.sys is a Verisign signed file. AsIO.sys appears to be a compressed file.

Important: Some malware disguises itself as AsIO.sys, particularly when not located in the C:\Windows\System32\drivers folder. Therefore, you should check the AsIO.sys process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

Installed by ASUS MB support software
  Richard P. Jones  
This file appears to be used by the Asus "PC Probe" for Asus motherboards.
It contains "\DosDevices\Asusgio" text string. Probably, it is a part of the ASUS graphic In/Out drivers.
System file for Asus Probe 2 diagnostic program
  T Munday  
This appears to be an "Audio stream In /Out" driver. Originally designed by Stienberg of Germany. It's a cross platform audio transfer protocol. It was installed as part of my ASUS motherboard drivers.
  Carlos   (further information)
Seem's? to be a driver for ASUS mother board.
I got the same error after upgrade too Windows 7, , just uninstall pc probe 2 andd install new version, worked for me.
ASIO. sys can be Audio Stream I/O driver (if you are using ASIO for your sound card) or ASus I/O sys file for their PCprobe/AI diagnostics (if you have ASUS mobo utilities installed)
it won`t let me open any of Asus utilities
  Greg Thomson  
Re-install the SixEngine software on the Win 7 Upgrade Kit DVD, labeled "Essentia Desktop PC"... Don't waste your time listening to tech support - they want to waste 3 hours of time by having you re-install Win 7...
Installed by Asus Apps: EPU6Engine, TurboV_EVO, TurboV_Remote, AISuite, Asus_UPDT, ProbeII, TProbe, Dangerous. Always crash with Windows7_64Bit
Asus Apps - for me AI Suite
ASUS Audio in/out driver system driver file.
  SomeOne   (further information)
It is a core windows file

Rating chart

Summary: Average user rating of AsIO.sys: based on 19 votes with 15 user comments. 9 users think AsIO.sys is essential for Windows or an installed application. 2 users think it's probably harmless. 7 users think it's neither essential nor dangerous. One user suspects danger.

Do you have additional information?
What do you know about AsIO.sys:
How would you rate it:
Link for more info:
Your Name:

Best practices for resolving AsIO issues

A clean and tidy computer is the key requirement for avoiding problems with AsIO. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the AsIO.sys process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

AsIO.sys [all]