Severeal common user settings and policies can be set using gpedit.msc (Group Policy Snap-in). This includes desktop, start menu, taskbar, contorl panel, logon, network and power management related settings etc. Have you ever wondered how to remove logoff or shutdown button from start menu? Or how to set wallpaper or screensaver in runtime? Or how to hide notification area or tooltip? There are so many such settings that can be done through gpedit.msc.
If your runtime configuration includes "Group Policy Core Administration MMC Snap-In" Component and some support components, you can use gpedit.msc in runtime to change above settings. Alternatively, you can use regmon (www.sysinternals.com) to identify the registry key corresponding to particular setting and use regedit to change the setting in runtime. The registry key related to most of the above settings are under the following registry branch:
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies (and sub branches - Explorer, Network, System etc.)
Once you identify the key corresponding to the setting, you can create that registry key under this branch and set the value to 0 (for disable) or 1(for enable). For example, if you want to remove logoff button from your start menu, you need to create the following registry key in runtime and set the value to 1(to enable):
This is same as enabling the following policy in gpedit.msc:
User configuration->Administrative Templates->Start menu and taskbar->"Remove Logoff on the start menu" (change to 'enabled' from 'not configured')