Error "Windows Installer service could not be accessed" occurs when you try to add or remove a program in Windows XP or Windows Server 2003

and then follow these steps.

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.

1. Determine the location of the Msiexec.exe file on your computer. To do this, follow these steps:
   1. Click Start, click Run, type %windir%\system32, and then click OK.
      
      
      Note�This step opens the folder where the�Msiexec.exe file is located.
   2. Note the location of the Msiexec.exe file. The location of the Msiexec.exe�file is a combination of the value in the�Address�box and the�Msiexec.exe file name itself.
      
      For example, if the�Address�box contains a value of�C:\Windows\system32, the location of the Msiexec.exe�file�is�C:\Windows\system32\Msiexec.exe.
2. Important 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, click the following article number to view the article in the Microsoft Knowledge Base:
   322756 How to back up and restore the registry in Windows
   
   
   Make sure that the location of the Msiexec.exe file in Registry Editor is correct. To do this, follow these steps:
   1. Click Start, click Run, type regedit in the Open box, and then click OK.
   2. Expand HKEY_LOCAL_MACHINE, expand SYSTEM, expand CurrentControlSet, expand Services, and then click MSIServer.
   3. In the right-pane, right-click ImagePath, and then click Modify.
   4. In the Value data�box, type the location of the�Msiexec.exe file that you determined in step 1, followed by the value of /V, and then click OK.
      
      For example, if the location of the Msiexec.exe file is C:\Windows\system32\Msiexec.exe, type the following text in the Value data text box:
      C:\WINDOWS\System32\msiexec.exe /V
   5. Click OK to close the Edit String dialog box.
   6. On the�File menu, click Exit to close Registry Editor.
3. Start your computer in safe mode, and then register the Msiexec.exe file. To do this, follow these steps:
   1. Click Start, and then click Turn off computer or Shut Down.
   2. Select the Restart option, and then click OK, or click Restart.
   3. Press F8 before the Windows screen appears.
   4. On the Windows Advanced Option menu, use the arrow keys to select the Safe Mode�option, and then press Enter.
   5. If you use a dual-boot or multiple-boot computer, select the appropriate operating system from the list that is displayed, and then press Enter.
   6. Log on to the computer.
   7. Click Start, click Run, type msiexec /regserver in the Open�box, and then click�OK.
      
      
      Note For 64-bit operating systems, you also have to reregister the 64-bit MSI installer. To do this, click Start, click Run, type %windir%\Syswow64\Msiexec /regserver in the Open box, and then click OK.
      
      On 64-bit editions of the Windows operating system, 32-bit binaries are located in %systemroot%\SysWow64 folder. The 64-bit binaries are located in the %systemroot%\System32 folder.
   8. Click Start, and then click Turn off computer or Shut Down.
   9. Select the Restart option, and then click OK, or click Restart.

If the issue still occurs, and you still receive the error message that is mentioned in the "Symptoms" section, follow the steps in Method 2.

and then follow these steps:

1. Click Start, click Run, type cmd in the Open box, and then click OK.
2. Type cd %windir%\system32, and then press Enter.
3. Type attrib -r -s -h dllcache, and then press Enter.
4. Type ren msi.dll msi.old, and then press Enter.
5. Type ren msiexec.exe msiexec.old, and then press Enter.
6. Type ren msihnd.dll msihnd.old, and then press Enter.
7. Type exit, and then press Enter.
8. At the command prompt, type exit, and then press Enter.�
9. Click Start, and then click Turn off computer or Shut Down.
10. Select the Restart option, and then click OK, or click Restart.
11. Log on to the computer.
12. Download and install the latest version of the Windows Installer. For more information about how to obtain the Windows Installer, click the following article number to view the article in the Microsoft Knowledge Base:
    893803 Windows Installer 3.1 v2 (3.1.4000.2435) is available
13. Click Start, and then click Turn off computer or Shut Down.
14. Select the Restart option, and then click OK, or click Restart.

The Windows Installer 4.0 is not available as a redistributable for Windows Vista. The Windows Installer 4.0 is included with the Windows Vista operating system.

If the methods described in this article do not resolve the problem, contact Microsoft Customer Support Services for more help.

This problem can also occur if the Startup Type property for the Windows Installer service is set to a value of Disable. To check whether the Windows Installer service is set to a value of Disable, follow these steps:

1. Click Start, click Run, type services.msc in the Open box, and then click OK.
2. In the Services (Local) list, right-click Windows Installer, and then click Properties.
3. If the Startup type drop-down list is set to a value of Disable, select the Manual option from the Startup type drop-down list, and then click OK.
4. On the File menu, click Exit.

�For more information about Windows Installer,�see Overview of Windows Installer on the Microsoft Developer Network (MSDN) website.� For more information about how to obtain the Windows Installer engine, click the following article number to view the article in the Microsoft Knowledge Base: