Step 1: Check Windows Installer service.

1. Click Start.
2. Type services.msc in the search box.
3. In the results list, right click on services.msc.
4. In the popped up menu, select Run as administrator.

5. In the window that opens, scroll down the list of services and find Windows Installer. Double-click it.
6. On the General tab under Service status, check the service is running.
7. If the service is not running, click Start button.

8. Make sure the service is running now.
9. Click OK.

Step 2: Re-register Windows Installer.

1. Click Start.
2. In the search box, type MSIEXEC /UNREGISTER and press Enter.

3. Click Start again.
4. In the search box, type MSIEXEC /REGSERVER and press Enter.

Disclaimer. The following steps are associated with editing the registry. Be very careful, because incorrect registry configuration can cause serious problems in the OS up to its crash. Changing these parameters you perform at your own risk.

Step 3: Cleaning the pending installation processes.

1. Click Start.
2. In the search box, type regedit and press Enter.

3. Go to the registry key: HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Installer \ InProgress. If there is no InProgress key, skip to point 5.
4. Remove all parameters in this section. If the section does not contain parameters, proceed to the next point.

5. Go to the registry key: HKEY_LOCAL_MACHINE \ System \ CurrentControlSet \ Control \ Session Manager \ PendingFileRenameOperations. If there is no PendingFileRenameOperation key, proceed to the next step.
6. Remove all parameters in this section. If the section does not contain parameters, proceed to the next step.

Step 4: Check permissions.

1. Go to the registry key: HKEY_LOCAL_MACHINE \ Software \ Microsoft \ Windows \ CurrentVersion \ Installer.
2. Right-click on the section title to open a menu, and then select Permissions.
3. In the dialog box, click on the SYSTEM item of the Group or user names list.
4. In the section Permissions for sure that the system has full control over Installer registry key.

After completing the steps, restart your computer.