diff --git a/doc/install_windows_manually.txt b/doc/install_windows_manually.txt
index c3e97df043..2f1ae22bcb 100644
--- a/doc/install_windows_manually.txt
+++ b/doc/install_windows_manually.txt
@@ -1,5 +1,5 @@
 --------------------------------------
-Firebird 2.1 manual installation notes
+Firebird 4.0 manual installation notes
 --------------------------------------
 
 Contents
@@ -8,6 +8,7 @@ Contents
 o Installation as a service
 o Execution as an application
 o Installation with a different service name
+o Initializing the Security Database
 o Uninstallation
 
 
@@ -67,6 +68,41 @@ parameter:
 NOTE: If you are running multiple Firebird services it is essential that you 
 do not configure the FIREBIRD environment variable at the system level.
 
+Initializing the Security Database
+----------------------------------
+The security database (security4.fdb) has no predefined users. This is intentional.
+You will need to create the user SYSDBA and set up the password for it 
+using SQL CREATE USER command syntax in embedded mode as your first step to getting
+access to databases and utilities.
+
+Initialization is performed in embedded mode using the isql utility. For an embedded connection, an authentication
+password is not required and will be ignored if you provide one. An embedded connection will work fine
+with no login credentials and "log you in" using your host credentials if you omit a user name. However, even
+though the user name is not subject to authentication, creating or modifying anything in the existing security
+database requires that the user be SYSDBA; otherwise, isql will throw a privilege error for the CREATE USER
+request.
+
+The SQL user management commands will work with any open database. Because the sample database employee.fdb 
+is present in your installation and already aliased in databases.conf, it is convenient to use
+it for the user management task.
+
+1. Stop the Firebird server. Firebird 4 caches connections to the security database aggressively. The presence
+   of server connections may prevent isql from establishing an embedded connection.
+2. In a suitable shell, start an isql interactive session, opening the employee database via its alias:
+    > isql -user sysdba employee
+3. Create the SYSDBA user:
+    SQL> create or alter user SYSDBA password 'StrongPassword';
+    SQL> commit;
+    SQL> quit;
+4. To complete the initialization, start the Firebird server again. Now you will be able to perform a network
+   login to databases, including the security database, using the password you assigned to SYSDBA.
+
+An effective password, using the default user manager Srp, can be up to 20 characters, although a password
+of up to 255 characters will be valid.
+
+The initialization can also be scripted using the file input option of isql with the content being same as interactive usage.
+> isql -i init.sql -user sysdba employee
+
 
 Uninstallation
 --------------