«The Windows Installer service could not be accessed» when you try to install Office

Office 365 ProPlus is being renamed to Microsoft 365 Apps for enterprise. For more information about this change, read this blog post.

Symptoms

When you try to install Microsoft Office, you may receive an error message that is similar to the following:

«The Windows Installer Service could not be accessed.»

Cause

This problem may occur if the Windows Installer files are damaged or missing.

Resolution

To resolve this problem, use one of the following methods.

Method 1: Use the Msconfig tool to confirm that the installer service is running

Click Start, and then click Run. (The screen shot for this step is listed below).

In the Open box, type msconfig, and then click OK. (The screen shot for this step is listed below).

On the Services tab, click to select the check box that is next to Windows Installer. (The screen shot for this step is listed below).

Click OK, and then click RestartВ to restart the computer. (The screen shot for this step is listed below).

Install Office again. When you are prompted to enter the product key, type the product key, and then click Next.

Office will be installed, and you will not be prompted for the product key when the programs start.

Method 2: Re-register Windows Installer

This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, see How to back up and restore the registry in Windows.

Note Because there are several versions of Microsoft Windows, the following steps may be different on your computer. If they are, see your product documentation to complete these steps.

To re-register Windows Installer, follow these steps.

Note If you cannot complete the following steps, go to method 3.

Click Start, and then click Search. (The screen shot for this step is listed below).

Click All files and folders. (The screen shot for this step is listed below).

In the File name box, type Msiexec.exe, and then click Search. (The screen shot for this step is listed below).

After the search is complete, make a note of the location of the Msiexec.exe file. The location of the file should be similar to the following example: C:\Windows\System32 (The screen shot for this step is listed below).

On the File menu, click Close to close the SearchВ dialog box. (The screen shot for this step is listed below).

Click Start, and then click Run. (The screen shot for this step is listed below).

In the Open box, type regedit, and then click OK. (The screen shot for this step is listed below).

Locate and then click the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer(The screen shot for this step is listed below).

In the right pane of the Registry Editor window, double-click ImagePath. (The screen shot for this step is listed below).

In the Edit String dialog box that appears, make sure that the string in the Value data box contains the correct path for the Msiexec.exe file that you determined in step 4.

Note The following is an example of the correct path, where drive is the drive where Windows is installed:

drive:\Windows\System32\msiexec.exe /V

If the Value data box does not contain the correct path, make changes to correct the path, and then click OK to close the Edit String dialog box. (The screen shot for this step is listed below).

On the File menu, click ExitВ to quit Registry Editor. (The screen shot for this step is listed below).

Start your computer in Safe mode, and then register the Msiexec.exe file. To do this, follow these steps:

Shut down your computer, and then restart your computer.

Restart your computer and press the F8 key on your keyboard. On a computer that is configured for booting to multiple operating systems, press the F8 key when you see the Boot menu.

Use the ARROW keys to select Safe Mode, and then press ENTER.

If the Boot menu appears again, and the words «Safe Mode» appear in blue at the bottom, select the installation that you want to start, and then press ENTER.

Log on to the computer.

Click Start, click Run, type msiexec /regserver in the Open box, and then click OK. (The screen shot for this step is listed below).

Shut down your computer, and then restart your computer normally.

If you still cannot install Microsoft Office successfully and you receive an error message that is similar to the message listed in the «Symptoms» section, go to Method 3.

Method 3: Try the methods that are listed in Microsoft Knowledge Base Article 319624

Try the methods that are listed in the following Microsoft Knowledge Base article:

319624 «Windows Installer Service could not be accessed» error message when installing application

Method 4: Reinstall Windows Installer

Note This method applies to Microsoft Windows 95, Microsoft Windows 98, Microsoft Windows Millennium Edition (Me), and Microsoft Windows NT 4.0. For Microsoft Windows 2000, Microsoft Windows XP, and Microsoft Windows Server 2003, either reapply the latest service pack or repair the operating system.

To reinstall the Windows Installer, follow these steps.

Click Start, and then click Run. (The screen shot for this step is listed below).

In the Open box, type cmd, and then click OK. (The screen shot for this step is listed below).

At the command prompt, type the following lines. Press ENTER after you type each line.

(The screen shot for this step is listed below).

ren msi.dll msi.old

(The screen shot for this step is listed below).

ren msiexec.exe msiexec.old

(The screen shot for this step is listed below).

ren msihnd.dll msihnd.old

(The screen shot for this step is listed below).

At the command prompt, type exit, and then press ENTER. (The screen shot for this step is listed below).

Restart your computer.

Update the Windows Installer files to the latest version. To do so, visit one of the following Microsoft Web sites, and then download and install Windows Installer 2.0.

Note Windows Installer 2.0 is included with Microsoft Windows XP. You do not have to perform this step if you are using Windows XP.

After the installation of the Windows Installer is complete, shut down and restart your computer normally before you install Microsoft Office.

More Information

For more information about how to restart Windows in Safe mode, see Advanced startup options (including safe mode).

Windows Installer

This documentation is intended for software developers who want to use Windows Installer to build installer packages for applications. If you’re looking for a redistributable for Windows Installer 4.5 and earlier, see this article. Note that there is no redistributable for Windows Installer 5.0. This version is included with the OS in Windows 7, Windows ServerВ 2008В R2, and later client and server releases (including Windows 10).

Microsoft Windows Installer is an installation and configuration service provided with Windows. The installer service enables customers to provide better corporate deployment and provides a standard format for component management. The installer also enables the advertisement of applications and features according to the operating system. For more information, see Platform Support of Advertisement.

This documentation describes Windows InstallerВ 5.0 and earlier versions. Not all the capabilities available in later Windows Installer versions are available in earlier versions. This documentation does not describe versions earlier than Windows InstallerВ 2.0. Installation packages and patches that are created for Windows InstallerВ 2.0 can still be installed by using Windows InstallerВ 3.0 and later.

Windows InstallerВ 3.0 and later, can install multiple patches with a single transaction that integrates installation progress, rollback, and reboots. The installer can apply patches in a specified order regardless of the order that the patches are provided to the system. Patching using Windows InstallerВ 3.0 only updates files affected by the patch and can be significantly faster than earlier installer versions. Patches installed with Windows Installer 3.0 or later can be uninstalled in any order to leave the state of the product the same as if the patch was never installed. Accounts with administrator privileges can use the API of Windows InstallerВ 3.0 and later to query and inventory product, feature, component, and patch information. The installer can be used to read, edit, and replace source lists for network, URL, and media sources. Administrators can enumerate across user and install contexts, and manage source lists from an external process.

Windows Installer 4.5 and later can install multiple installation packages using transaction processing. If all the packages in the transaction cannot be installed successfully, or if the user cancels the installation, the Windows Installer can roll back changes and restore the computer to its original state. The installer ensures that all the packages belonging to a multiple-package transaction are installed or none of the packages are installed.

Beginning with Windows Installer 5.0, a package can be authored to secure new accounts, Windows Services, files, folders, and registry keys. The package can specify a security descriptor that denies permissions, specifies inheritance of permissions from a parent resource, or specifies the permissions of a new account. For information, see Securing Resources. The Windows Installer 5.0 service can enumerate all components installed on the computer and obtain the key path for the component. For more information, see Enumerating Components. By Using Services Configuration, Windows Installer 5.0 packages can customize the services on a computer. Setup developers can use Windows Installer 5.0 and Single Package Authoring to develop single installation packages capable of installing an application in either the per-machine or per-user installation context.

Where applicable

Windows Installer enables the efficient installation and configuration of your products and applications running on Windows. The installer provides new capabilities to advertise features without installing them, to install products on demand, and to add user customizations.

Windows Installer 5.0 running on Windows ServerВ 2012 or WindowsВ 8 supports the installation of approved apps on WindowsВ RT. A Windows Installer package, patch, or transform that has not been signed by Microsoft cannot be installed on WindowsВ RT. The Template Summary property indicates the platform that is compatible with an installation database and in this case should include the value for WindowsВ RT.

Windows Installer is intended for the development of desktop style applications.

Developer audience

This documentation is intended for software developers who want to make applications that use Windows Installer. It provides general background information about installation packages and the installer service. It contains complete descriptions of the application programming interface and elements of the installer database. This documentation also contains supplemental information for developers who want to use a table editor or a package creation tool to make or maintain an installation.

Run-time requirements

Windows InstallerВ 5.0 is included with, Windows 7, Windows ServerВ 2008В R2, and later releases. There is no redistributable for Windows Installer 5.0.

Versions earlier than Windows Installer 5.0 were released with Windows ServerВ 2008, WindowsВ Vista, Windows ServerВ 2003, WindowsВ XP, and WindowsВ 2000. Windows Installer Redistributables are available for Windows Installer 4.5 and some earlier versions.

Windows InstallerВ 4.5 requires Windows ServerВ 2008, WindowsВ Vista, WindowsВ XP with Service PackВ 2 (SP2) and later, and Windows ServerВ 2003 with Service PackВ 1 (SP1) and later.

Windows InstallerВ 4.0 requires WindowsВ Vista or Windows ServerВ 2008. There is no redistributable for installing Windows InstallerВ 4.0 on other operating systems. An updated version of Windows InstallerВ 4.0, which does not add any new features, is available in WindowsВ Vista with Service PackВ 1 (SP1) and Windows ServerВ 2008.

Windows InstallerВ 3.1 requires Windows ServerВ 2003, WindowsВ XP, or WindowsВ 2000 with Service PackВ 3 (SP3).

Windows InstallerВ 3.0 requires Windows ServerВ 2003, WindowsВ XP, or WindowsВ 2000 with SP3. Windows InstallerВ 3.0 is included in WindowsВ XP with Service PackВ 2 (SP2). It is available as a redistributable for WindowsВ 2000 Server with Service PackВ 3 (SP3) and WindowsВ 2000 Server with Service PackВ 4 (SP4), WindowsВ XP RTM and WindowsВ XP with Service PackВ 1 (SP1), and Windows ServerВ 2003 RTM.

Windows InstallerВ 2.0 is contained in Windows ServerВ 2003 and WindowsВ XP.

Windows InstallerВ 2.0 is available as a package for installing or upgrading to Windows InstallerВ 2.0 on WindowsВ 2000. This package should not be used to install or upgrade Windows InstallerВ 2.0 on Windows ServerВ 2003 and WindowsВ XP.