Users and groups on Windows

After a user is set in Windows XP, the user can not only protect the security of the local computer, but also protect the data security in the network.
(1) User Management
To log on to a Windows XP computer, you must have a user account, which is a file that defines all information about Windows XP users, including the user name and user logon password. In Windows XP, the user account is created and managed by the administrator of the local computer, and each user is granted certain permissions. When a user logs on to the computer, Windows XP checks the user name and password.
1. Create a local user
After Windows XP is installed, the system automatically creates two accounts, namely administrator and guest. The Administrator account has the highest permissions on the Local Computer and has absolute control over the local computer. Guest is set for users who do not have their own accounts in the system, this account only has small permissions. Therefore, to create a local user on the local machine, the administrator or a user with equivalent permissions must perform this operation.
(1) log on to the computer by the administrator or a user with equivalent permissions, right-click the "my computer" icon, and select the "manage" command from the shortcut menu, open the "Computer Management" dialog box.
(2) double-click to expand the "local user and group" item. Select the "user" option. All existing user accounts are displayed in the right window.
(3) Right-click the window on the right and select the "new user" command from the shortcut menu to open the "new user" dialog box.
(4) enter the user name, password, and other information in the dialog box, enter the same user password in the "Confirm Password" box, and then click "CREATE" to create a local user. You can add other new accounts. Click "close" To End User Creation.
Note: When a newly created user is not granted certain permissions by the Administrator, the user will be added to the user group. The user in this group is a restricted user, they can only operate on computers and save documents, but cannot modify system files or configurations. administrators can add new users to other groups to change their permissions.
2. delete or disable a user account
In Windows XP, to prevent local users from logging on to the local machine, you can disable or delete their accounts.
(1) follow the above steps to open the "Computer Management" dialog box, and expand the "user" option in "local users and groups.
(2) double-click the user account to be deactivated, open its properties dialog box, select the "account deactivated" check box, and click "OK. At this time, you will find that the "X" mark appears on the Disabled Account icon to indicate that the user account has been disabled. To re-enable this user account, you only need to cancel this check box.
(3) to delete a user account, right-click the user account to be deleted and select the "delete" command from the shortcut menu, in the displayed dialog box, click "yes" to delete the user account.
(2) User Group Management
After Windows XP is installed, the system automatically creates six local working groups, each of which has different operation permissions on the local computer.
Administrator group: Administrator group, which has full control over the local computer. It is the only group in the system that is granted all built-in permissions and capabilities.
Backup Operators group: Backup operator group. This group can back up or restore files on the computer. It can log on or shut down the system, but cannot change any security settings.
Power Users Group: a standard user group. Users in this group can change computer settings and setup programs, but cannot view documents created by other users.
Users Group: Restricted User Group. Users in this group can run programs and save documents, but cannot modify computer settings, install programs, and view documents created by other users.
Guests group: Guest Workgroup, which allows temporary users to log on to computers using the guests account. They are given minimal permissions. Users in the guests group can shut down the system.
Replicator group: This group supports directory replication. Only Members in the replicator group can log on to the backup server of the domain controller using the domain user account.
The default account and the account created by the Administrator on the local machine are added to different groups. The computer uses the group to authorize the user to execute tasks on the local computer.
1. Create a group
(1) log on to the computer by the administrator or a user with equivalent permissions, right-click the "my computer" icon, and select the "manage" command from the shortcut menu, open the "Computer Management" dialog box.
(2) In the left-side window, double-click to expand the "local users and groups" item. Select the "Group" option. The created local group is displayed in the right window.
(3) Right-click the window on the right and select the "new group" command from the shortcut menu to open the "new group" dialog box.
(4) In the "group name" box, enter the name of the new group, enter the description of the group account in the "Description" box, and then click "CREATE" to complete the creation of the Working Group.
The new group does not have any permissions at this time. You can use the Group Policy Editor to grant certain permissions to the new group.
2. Add a user to the group
Adding a user to a group is actually assigning the group power to the users in the group. A group can contain multiple users, and a user can belong to multiple groups. In Windows XP, users in the Administrator group, Power Users Group, and Users group have the right to add users to the local group. The difference is that users in the Administrator group, users in the Power Users Group can only add users to the Power Users Group, Users Group, and guests group; users in the Users Group can only add users to the local group they created.
(1) follow the above steps to open the "Computer Management" dialog box, and expand the "Group" option in "local users and groups. The created group is displayed in the right window.
(2) In the right window, right-click the user you want to add to the group to, and click "add to group" in the shortcut menu to open the Properties dialog box.
(3) Click "add" to open the "Select User" dialog box. In the user list at the bottom of the dialog box, select the user you want to add to the current group and click OK to return to the properties dialog box.
(4) All users added to the current group are displayed in the "members" list. You can add multiple users to the current group in the same way. After adding, click OK.
The user added to the group will have all permissions for the group. If the user belongs to multiple groups, the user will have permissions for multiple groups, the permissions of the highest permission group shall prevail.
3. delete a group
In Windows XP, apart from the default six groups, other newly created local groups can be deleted. Users in the Administrator group can delete any created group, while users in the Users Group and the Power Users Group can only delete the group they created.
(1) Open the "Computer Management" dialog box, and expand the "Group" option in the "local users and groups" item. The created group is displayed in the right window.
(2) Right-click the Local Group to be deleted, select the "delete" command from the shortcut menu, and click the "yes" button in the pop-up prompt box to delete the local group.
4. Set permissions for the Local Group
Setting local group permissions is actually setting user permissions. When the Administrator grants permissions to a working group, this permission is also granted to all members in the group.
(1) Click "start", select the "run" command, enter "MMC" in the "run" dialog box, and click "OK, open the "console" window.
(2) Click the "file" menu and select the "Add/delete snap-in" command to open the "Add/delete snap-in" dialog box. Click the Add button to open the add independent management unit dialog box, and select a group policy management unit from the available independent management units list. Click Add to return to the console window.
(3) In the left-side console directory tree, expand "Local Computer Policy", "Computer Configuration", "Windows Settings", "Security Settings", "Local Settings", and "user permission assignment. In this case, all available permissions and groups that currently have this permission are displayed in the right window.
(4) After selecting the permissions to be granted to the Local Group, click the "properties" command in the "operations" menu to open the "Create object properties" dialog box.
(5) Click the "add" button to open the "Select User" dialog box. In the dialog box, select the group to which you want to grant permissions, and click the "add" button, add the group to the list. Click "OK" to return to the "Create object attributes" dialog box. The newly added group is displayed in the member list. Click OK.
5. Quick User Switching
Quick User Switching allows each user to share a computer just like their own computer. You do not have to log out of other users and decide whether to interrupt their currently running applications or save their documents, and quickly switch to another user.
(1) Click "start" and select "logout". In the displayed "log out of windows" dialog box, click "switch user" to log out of the current user.

(2) In the displayed logon interface, you only need to select the user you want to switch to and enter the logon password to quickly switch between multiple users.

Create a new ymc user and add it to the ora_dba group. Then, the user can access Oracle through operating system authentication.