Earlier versions of Windows had a single Control Panel-a collection of icons that led to assorted configuration tools and settings. As computers became more complex, the number of icons in Control Panel grew, giving cause to users plunging into Control Panel for the first time.

Windows XP addresses this confusion by dividing Control Panel icons into categories, and putting a friendly face on the new Control Panel.

Experienced users are likely to find the new Control Panel more of a hindrance than an aid, but fortunately, it’s easy to revert to the single-level Control Panel of old.

Resetting Control Panel will probably be one of the first changes you’ll make on a new computer.

Some programs and devices install their own Control Panel applications. These applications will normally go into the proper category if you use Category view, but applications not written to Windows XP specifications might not be as accommodating. If you want to change the category in which a Control Panel application appears, you can do so with a registry edit.

The HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Control Panel\Extended Properties\
{305CA226-D286-468e-B848-2B2E8E697B74} 2 key contains the category information.

Each DWORD value, which uses the full path to a .cpl (Control Panel) file as its name, should have one of the following settings:

Category	Value Data
Accessibility Options	0x00000007
Add or Remove Programs	0x00000008
Appearance and Themes	0x00000001
Date, Time, Language, and Regional Options	0x00000006
Network and Internet Connections	0x00000003
Other Control Panel Options	0x00000000
Performance and Maintenance	0x00000005
Printers and Other Hardware	0x00000002
Sounds, Speech, and Audio Devices	0x00000004
User Accounts	0x00000009
No category	0xFFFFFFFF

Check out MS article on the subject: How to Add a Control Panel Tool to a Category