The default behavior of a Windows XP Professional non-domain computer is to hide the Security tab.

NOTE: Security can only be set on a NTFS partition.

When Use simple file sharing (Recommended) is checked on the View tab of Windows Explorer's Folder Options, you are presented with the Simple File Sharing UI instead of the classic Security and Sharing tabs, except when booting to Safe mode.

The Simple File Sharing UI is different for the My Documents folder. The following is displayed:

Only I have access to this folder
This folder is shared on the network
Share name:
Allow other users to change my files

All other folders display:

Share name:
Allow other users to change my files

When a user password is created, the Protect The My Documents Folder option is also displayed.

You can show the classic security UI:

1. Use the Registry Editor to navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa.

2. Double-click the Forceguest Value Name, a REG_DWORD data type, and set the data value to 0.

3. Shutdown and restart your computer.

4. Verify that the Use simple file sharing (Recommended) box is cleared, or clear it.

NOTE: See When you try to use Netdom.exe to join a Windows XP Professional computer to your domain, it fails with 'The specified network password is not correct'?