MSU is an update installer file format used by Windows Update application included in Windows Vista operating system. MSU file stores file and application updates (security updates, system updates, or patches).
Each MSU file contains the following elements:
MSU is a proprietary format. MSU files are typically compressed to save disk space as Windows update packages are released frequently and can be quite large.
Udates in MSU files are installed by Windows Update tool, which is run by Wusa.exe program located in System32 folder on Windows system. Installer uses Windows Update Agent API for applying updates. Contents of MSU files can be extracted manually and then installed using appropriate Windows command line instructions.
Programs that can handle MSU files are as follows. MSU files can be encountered on all system platforms, including mobile, yet there is no guarantee each will properly support such files.
Being unable to open files with MSU extension can be have various origins. Fortunately, most common problems with MSU files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. The list below will guide you through the process of addressing the encountered problem.
Problems with opening and working with MSU files are most probably having to do with no proper software compatible with MSU files being present on your machine. This issue can be addressed by downloading and installing Microsoft Windows Update or different compatible program, such as Microsoft Windows 8, Microsoft Windows Vista, Microsoft Windows 7. On the top of the page a list that contains all programs grouped based on operating systems supported can be found. The safest method of downloading Microsoft Windows Update installed is by going to developer’s website () and downloading the software using provided links.
If the problems with opening MSU files still occur even after installing Microsoft Windows Update, it is possible that you have an outdated version of the software. Check the developer’s website whether a newer version of Microsoft Windows Update is available. Software developers may implement support for more modern file formats in updated versions of their products. If you have an older version of Microsoft Windows Update installed, it may not support MSU format. The most recent version of Microsoft Windows Update is backward compatible and can handle file formats supported by older versions of the software.
If the issue has not been solved in the previous step, you should associate MSU files with latest version of Microsoft Windows Update you have installed on your device. The method is quite simple and varies little across operating systems.
Selecting the first-choice application in Windows
Selecting the first-choice application in Mac OS
If you followed the instructions form the previous steps yet the issue is still not solved, you should verify the MSU file in question. Problems with opening the file may arise due to various reasons.
If the MSU is indeed infected, it is possible that the malware is blocking it from opening. Scan the MSU file as well as your computer for malware or viruses. If the scanner detected that the MSU file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.
If you obtained the problematic MSU 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 MSU extension was interrupted and the file data is defective. Download the file again from the same source.
Some files require elevated access rights to open them. Log out of your current account and log in to an account with sufficient access privileges. Then open the Windows Vista Update Package file.
The operating systems may note enough free resources to run the application that support MSU files. Close all running programs and try opening the MSU file.
Up-to-date system and drivers not only makes your computer more secure, but also may solve problems with Windows Vista Update Package file. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle MSU files.
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