If, for security reasons, you wish to hide or remove the EXISTING DEFAULT Control Panel Applets, or for convenience sake add YOUR OWN applets to the Control Panel, here is how you can do it.

How To Remove Control Panel Applets.
Type gpedit.msc in Vista's Start Menu Search Bar, hit Enter, to open the Group Policy Editor. Expand Administrative Templates > Click Control Panel > Show only specified Control Panel Applets > Properties.  A dialog box will open. Click on Enable. The Show button will come alive. Click on Show and a new dialog box will open.

Those items which are NOT on this list WILL NOT not be displayed, IF this is enabled. You will have to ADD the control panel applet's NAME, (eg: appwiz.cpl) which you WANT displayed in the Control Panel. But this is easier said than done, and it is rather painstaking work, as you need to KNOW the names ! Do click and read whatever is written in the 'Explain' tab. This way you can choose which applets to hide or show in the Control Panel. 
 
To find out the Control Panel applet names you may visit WinVistaClub.

How To Add Your Own Control Panel Applets.
"Adding & Registering YOUR OWN applet & tasks to Control Panel is easier in Windows Vista. Software developers can easily add their own applets and tasks to Control Panel. 

There are three types of Control Panel applets: command objects, shell folders, and CPLs. Command objects are applets that run commands specified in the registry. Shell folders are applets that open up in the Control Panel. CPLs implement the CplApplet function. Command objects are the easiest to implement.

The process of adding applets to Control Panel in previous versions of Windows is not as easy as using command objects because the applets have to implement the CplApplet interface. Although the CplApplet interface is still supported in Windows Vista, using command objects is encouraged since it is easier to implement. 

Now, in Windows Vista, you can just write an executable (.exe), register it as a command object and the applet appears in Control Panel .... "