ASU File Extension

What is ASU file?

Full format name of files that use ASU extension is ToolBook Package Definition. SumTotal Systems, Inc. defined the ToolBook Package Definition format standard. ASU files are supported by software applications available for devices running Windows. ASU file format, along with 1305 other file formats, belongs to the Settings Files category. ToolBook is by far the most used program for working with ASU files. ToolBook software was developed by SumTotal Systems, Inc., and on its official website you may find more information about ASU files or the ToolBook software program.

Programs which support ASU file extension

Programs that can handle ASU files are as follows. Files with ASU extension, just like any other file formats, can be found on any operating system. The files in question may be transferred to other devices, be it mobile or stationary, yet not all systems may be capable of properly handling such files.

How to open file with ASU extension?

There can be multiple causes why you have problems with opening ASU files on given system. On the bright side, the most encountered issues pertaining to ToolBook Package Definition files aren’t complex. In most cases they can be addressed swiftly and effectively without assistance from a specialist. The list below will guide you through the process of addressing the encountered problem.

Step 1. Download and install ToolBook

The most common reason for such problems is the lack of proper applications that supports ASU files installed on the system. The solution is straightforward, just download and install ToolBook. The full list of programs grouped by operating systems can be found above. If you want to download ToolBook installer in the most secured manner, we suggest you visit SumTotal Systems, Inc. website and download from their official repositories.

Step 2. Check the version of ToolBook and update if needed

If you already have ToolBook installed on your systems and ASU files are still not opened properly, check if you have the latest version of the software. It may also happen that software creators by updating their applications add compatibility with other, newer file formats. The reason that ToolBook cannot handle files with ASU may be that the software is outdated. The latest version of ToolBook should support all file formats that where compatible with older versions of the software.

Step 3. Associate ToolBook Package Definition files with ToolBook

If the issue has not been solved in the previous step, you should associate ASU files with latest version of ToolBook you have installed on your device. The process of associating file formats with default application may differ in details depending on platform, but the basic procedure is very similar.

Selecting the first-choice application in Windows

• Choose the Open with entry from the file menu accessed by right-mouse clicking on the ASU file
• Select Choose another app → More apps
• The last step is to select Look for another app on this PC option supply the directory path to the folder where ToolBook is installed. Now all that is left is to confirm your choice by selecting Always use this app to open ASU files and clicking OK.

Selecting the first-choice application in Mac OS

• Right-click the ASU file and select Information
• Open the Open with section by clicking its name
• Select the appropriate software and save your settings by clicking Change all
• Finally, a This change will be applied to all files with ASU extension message should pop-up. Click Continue button in order to confirm your choice.

Step 4. Check the ASU for errors

You closely followed the steps listed in points 1-3, but the problem is still present? You should check whether the file is a proper ASU file. Problems with opening the file may arise due to various reasons.

1. Verify that the ASU in question is not infected with a computer virus

If the file is infected, the malware that resides in the ASU file hinders attempts to open it. Scan the ASU file as well as your computer for malware or viruses. If the scanner detected that the ASU file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Check whether the file is corrupted or damaged

If you obtained the problematic ASU file from a third party, ask them to supply you with another copy. During the copy process of the file errors may occurred rendering the file incomplete or corrupted. This could be the source of encountered problems with the file. It could happen the the download process of file with ASU extension was interrupted and the file data is defective. Download the file again from the same source.

3. Check if the user that you are logged as has administrative privileges.

There is a possibility that the file in question can only be accessed by users with sufficient system privileges. Log in using an administrative account and see If this solves the problem.

4. Check whether your system can handle ToolBook

If the system is under havy load, it may not be able to handle the program that you use to open files with ASU extension. In this case close the other applications.

5. Verify that your operating system and drivers are up to date

Regularly updated system, drivers, and programs keep your computer secure. This may also prevent problems with ToolBook Package Definition files. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle ASU files.

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