What is registry?
The Registry is the central hierarchical database used in Microsoft Windows operating
system used to store informati on necessary to configure the system for one or more
users, applications and hardware devices.

Why do I need to clean the registry?
When you install an application, a new registry entries will be created. These entries will
automatically be deleted when you uninstall the application. Unfortunately, it does not
always work that way. Sometimes, you will find that some applications fail to remove their
own registry entries. These entries will become obsolete. Over time, Windows Registry
begins to hold data that are invalid and obsolete. This invalid data eventually accumulate
in the Registry, slowing Windows down, whereby compromising PC performance and
causing other problems. So, to keep your computer in top performance, it is recommended
to periodically clean your Windows registry.

All section of Wise Registry Cleaner
Components SubSystem: This section can find obsolete Activex/COM entries and repair
them.

What is an Active X control?
An Active X control can be defined as a small applet or software component that can be
reused over and over again. These encapsulated software programs or applets can either
be visual or non visual. They are easy to create and can be included in many applications
that run on the Windows platform.For instance, if you have created an Access Database
and would like to add more functionality to it, there are many different Active X Controls
available. One control that is used widely in MS Access is the Dropdown List Box. This is a
field that can expand to show dozens of choices that can easily be selected. Active X
Controls make it easier to add functionality, as well as complete a task quickly.

Why I need this section?
An Active X control already been remove, but some keys still in registry, when Windows run
some application that need this Active X control, you will get a error. And when the
Windows start, it load some Active X information and regardless of whether the correct
information, this time your Windows will become slow. So, you need use this section.

Software Section: This section can find obsolete and invalid information of software, then
remove them.
Application Paths: Find and remove invalid application information.
File Types: This section can find invalid and empty information of file association.
Help Files: This section can find invalid and empty information of help files.
Fonts: This section can find invalid and empty information of fonts.
Shared DLL: This section can find invalid and unused .dll files.

What is a dll?
Short for Dynamic Link Library, a library of executable functions or data that can be used by
a Windows application. Typically, a DLL provides one or more particular functions and a
program accesses the functions by creating either a static or dynamic link to the DLL. A
static link remains constant during program execution while a dynamic link is created by the
program as needed. DLLs can also contain just data. DLL files usually end with the
extension .dll,.exe., drv, or .fon. A DLL can be used by several applications at the same
time. Some DLLs are provided with the Windows operating system and available for any
Windows application. Other DLLs are written for a particular application and are loaded
with the application.
User MRU Lists: This section can find and erase user MRU lists.

What is MRU Lists?
Windows contains a number of most-recently-used (MRU) lists.
These MRU lists contain information such as the names and/or locations of the last files you
have accessed. They are located ALL OVER your registry, and for almost ANY file type. By
looking at these MRU lists, someone could determine what files you opened/saved/looked
at, what their file names were, and much more! (And, in many cases, the lists are displayed
in drop-down menus automatically.)
Uninstall Section: This section can find obsolete and invalid uninstall information.
Start Menu: This section can find obsolete and invalid start menu entries.
Startup Program: This section can find invalid startup program.
Sound and AppEvents: This section can find obsolete and invalid sound files and
appevents files.
IE Url History: This section can find and erase IE Url History.

About Wise Disk Cleaner

Extensions:

Below these extensions may also belong to junk files: (But, we can not be sure)

*.bmk *.cam *.cb *.cln *.cnt *.da1 *.da2 *.diz *.fix *.ign *.ink *.lgc *.lge *.lic *.new *.out * .par *.pvt *.query *.syd *.umb *.~mp *.!!! *.lhx

PS: If you know more extension of junk files, please tell us, thank you!