Westhen trying to add, install, uninstall or remove a plan from Windows operating system, the setup will halt with the following error message, which may happen in all editions of Windows Me (Millennium Edition), Windows 98, Windows NT 4.0, Windows 2000, Windows XP and Windows 2003 with or without service pack:

The Windows Installer Service could non be accessed. This can occur if you lot are running Windows in rubber mode, or the Windows Installer is non correctly installed. Contact your support personnel for assistance.

This error symptom is nigh likely acquired by the Windows Installer files are damaged or are missing, or Windows Installer Service is unregistered or damaged. Other reason can be incorrect permission event on the related registry keys that Windows Installer trying to access. The error will only occurred when the program's setup installer uses the Windows Installer Microsoft Software Installation (MSI) package file.

Microsoft provides various possible solutions and resolutions for dissimilar scenarios, equally in KB319624 (for Microsoft Windows Installer 1.0 and 2.0 in Windows NT iv.0 SP6, Windows 2000 SP1, SP2 and SP3), KB315353 (for Windows Vista and Windows seven) and KB315346 (for Windows XP Professional and Home Edition, Windows 2000 Server, Advanced Server, and Pro Ed, Windows NT Server four.0 Std and Developer Edition, Windows ME and Windows 98 SE), KB324516 (for Microsoft Function 2007, 2003, XP, 2000), KB217521 (for Office 2000), and KB873280 (for Coin 2002, 2003, 2004, 2005) (dead link).

The common methods by and large recommended to solve the "Windows Installer Service Could Not Be Accessed" fault is by unregistering (MSIEXEC /UNREGISTER) and then re-registering (MSIEXEC /REGSERVER) the Windows Installer, in Safe Style if need to. Otherwise, verify that System business relationship has total control access permissions to the HKEY_CLASSES_ROOT hive in the Windows registry or reinstall Windows Installer with Windows Installer 3.1 Redistributable (v2).

If you still facing the Windows Installer finish error afterwards performing recommended steps provided by Microsoft Cognition Base of operations articles, try to ensure that Windows Installer service is running, or force start information technology.

  1. Open up Run, and blazon in services.msc then printing Enter. Alternatively, go to Control Panel -> Ambassador Tools -> Services.
  2. Locate Windows Installer in the all install services listing.
  3. Verify that the Status is Started. If the Status column is blank, right click on Windows Installer and select Start.
  4. If you get mistake trying to strength start the Windows Installer service, try to modify the Startup Blazon to Automatic (default is Manual), and and so restart the computer.

The above steps tin also be performed via MSConfig to set Windows Installer service to auto start on boot upward.