When you right-click the Taskbar, the "Lock the Taskbar" option may be greyed out. This is due to a group policy / registry setting.





To unlock the Taskbar, try this:

Open Registry Editor (regedit.exe) and navigate to:

HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ Explorer

In the right-pane, delete the LockTaskbar value, and quit Registry Editor


For Windows XP Professional, you can also disable this using Group Policy Editor:

Click Start, Run and type GPEDIT.MSC

User Configuration | Administrative Templates | Start Menu and Taskbar

Set Lock the Taskbar policy to Not Configured