Are the dreaded Windows Installer Error 1402 Could not open key pop-ups driving you mad while trying to update Adobe Reader? Microsoft Office? Some other program that uses Windows Installer? After all, you cannot even uninstall or repair the programs until you’ve fixed the darn permissions.
The same issue can also cause Windows Installer Error 1603 – a newer version is already installed – while upgrading software. Alternatively, for error 1603, you need to run the installer with elevated rights: right-click or touch and hold the executable or .msi package and choose Run as administrator.
Here’s how to kick the sneaky little cause out of your Windows computer for good. Let’s take the good old Reader as an example here: where is that UNKNOWN registry key and why do you need to verify that you have sufficient access to that key, or contact your support personnel?
Launching Windows Registry Editor
Obviously, I am your support personnel today – as long as you do have administrative rights to the troublesome computer. 😉 If your user account is a member of the Administrators group, use keyboard shortcut Windows Key+R to open the Run dialog, type regedit and click OK.
If you are wise enough to be running everything as a standard user in Windows Vista, 7 and 10, you can open the Start menu, type regedit, right-click the result and select Run as administrator. The same applies to Windows 8 and 8.1 Start screen.
As a standard user in Windows XP, open Windows Explorer (keyboard shortcut Windows Key+E), navigate to Windows\System32 folder, locate the regedit.exe file, right-click it and choose Run as administrator.
Alright, Registry Editor is now open. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18, right-click Components and select Permissions from the menu.
First, let me remind you that messing with Registry entries the wrong way can easily make Windows unbootable. Do not do anything else here unless you are the guru of Microsoft universe! 😛
Second, the cause for the Windows Installer errors is usually not in one key only – so searching for that particular key, resetting its permissions and launching installer program again will probably get you to just another freaking Error 1402 dialog and failed installation attempt.
Let’s deal with it like a boss instead: in the Permissions for Components window, click Advanced. Yup, the dialog is exactly the same when you’re messing with NTFS permissions for a drive, folder or file.
Changing ownership for the Components key in Windows XP, Vista and 7
First, we need to take ownership of all Windows Installer entries to replace access rights in the second step. Only Satya Nadella knew why these permissions go wrong, but he lost the yellow post-it and now no one remembers… just kidding… or am I? 😀
In Windows XP, Vista and 7, open the Owner tab, click Administrators in the Change owner to list, tick the Replace owner on subcontainers and objects check box and click OK. You might see an error pop up after the process completes, just ignore it.
Continue to the replacing user permissions section.
Changing ownership for the Components key in Windows 8, 8.1 and 10
In Windows 8/8.1 and 10, click Change after the Owner’s name on the top left of the window.
Then type system and click Check Names. The object name should now be underlined and turn into all caps. Click OK.
Finally, the Replace owner on subcontainers and objects check box appears for Windows 8, 8.1 and 10 users. Tick it and then click OK.
Again, error(s) during the owner change is/are completely normal and expected.
Replacing user permissions for the Components key in all Windows versions
The Advanced Security Settings for Components window closes by itself. Click that Advanced button again and make sure to open the Permissions tab this time. Turn on the Replace all child object permissions with inheritable permissions from this object option and click OK.
If you changed the registry key owner to Administrators group in the first step, change it back to SYSTEM account now as shown in the Windows 8/8.1/10 example.
Guess what? 🙂 After closing Registry Editor, relaunch the setup program and the Windows Installer error 1402 and 1603 are gone! You can now install, update, remove or repair programs like you used to.