Issues while installing PostgreSQL in Windows 10

Did you install postgresql with administrator-privileges?

This might be due to a privilege-issue, you can try to:

• Create a new user account, called postgres

• Add the new account to the Administrators and Power Users groups

• Restart the computer

• Run a command prompt as the postgres user, using the command:runas /user:postgres cmd.exe

• Run the installer from the postgres command window

• Delete the postgres user account, as well as the user directory

Another option is to:

1. Uninstall PostgreSQL

2. Delete the postgres user if it still exists.

    net user postgres /delete 

3. Create the postgres user with a password

    net user /add postgres <password> 

4. Add the postgres user to the Administrators group

    net localgroup administrators postgres /add 

5a. Add the postgres user to the Power Users group

 net localgroup "power users" postgres /add 

5b. Add the postgres user to the administrator's local-group

 net localgroup Administrators postgres /add 

6. Run a command window as the postgres user

    runas /user:postgres cmd.exe 

7. Run the install file from within the command window.

    C:\Download\postgresql-9.6.12-windows.exe // or whatever version you are using 

   This should run the installation successfully.

8. Remove the postgres user from the Administrators group.

    net localgroup administrators postgres /delete 

as mentioned by @Imraan on DBA -> Link

Edit in regards to @Youssef's comment:

Depending on the version and scenario, the user postgres needs to be added to administrator's localgroup instead of power users.

Short overview about power-users from superuser SE:

Note: in Windows 7 and above, Power Users only exists for legacy purposes, and is the same as ordinary Users, unless an admin explicitly adds extra rights to the group.

Power-users may:

• Run legacy applications, in addition to Windows 2000 or Windows XP Professional certified applications.

• Install programs that do not modify operating system files or install system services.

• Customize systemwide resources including printers, date, time, power options, and other Control Panel resources.

• Create and manage local user accounts and groups.

• Stop and start system services which are not started by default.

• Power Users do not have permission to add themselves to the Administrators group.

• Power Users do not have access to the data of other users on an NTFS volume, unless those users grant them permission.

As for me, all I had to do to was to run the installer as an administrator

If the previous answers did not help, check the password you insert. I had the same issue and, as mentioned in this post, I just had to enter an alphanumeric password and I could finish the installation without further problems.