CCleaner can remove these advanced Windows files:
Old Prefetch Data - (XP only) To run quickly,
Windows uses prefetch files to store information about programs
that you frequently use. The Cleaner deletes old prefetch data for
programs that no longer exist or haven't been used in a long
time.
Menu Order Cache - When you drag and drop items
on the Start menu into different locations, Windows stores this
information in the Menu Order Cache.
Tray Notifications Cache - This cache stores
information about any items that have ever appeared in your System
Tray, and whether or not you have set them to Hide, Hide When
Inactive, or Always Show.
Window Size/Location Cache - When you open and
close Windows Explorer, Windows records folder settings for window
position, sort order, columns, folder type, toolbar toggles, and
search result views.
User Assist History - User Assist History is a
built-in monitoring feature of Windows that records when you access
programs, shortcuts, Control Panel applets, and possibly even Web
sites.
IIS Log Files - Microsoft's IIS server keeps
logs of its activities on your system.
Hotfix Uninstallers - (XP only) Every time you
download and run a Hotfix from Microsoft, Windows stores an
uninstallation program for that Hotfix on your system.
Custom Files and Folders - This setting relates
to CCleaner rather than any part of Windows. If you select Custom
Files and Folders, CCleaner will use the information in the Include and Exclude part of its Advanced
section to add or ignore files, folders, and Registry keys
while cleaning.
Wipe Free Space - When you delete files from
your hard drive, Windows only deletes the reference to the files,
not the files themselves. Over time, the contents of the files will
be overwritten as Windows writes new files, but it's possible to
recover some or all parts of deleted files.
You can prevent this by using the Wipe Free Space option. For
more information, see this
topic.
MUI Cache - Each application on your computer
has a base .EXE file (for example, Microsoft Word has WINWORD.EXE).
Each time you start an application, Windows extracts the formal
name for the application (such as "Microsoft Word") from the .EXE
file and stores it in a Registry key called the MUICache. You can
set CCleaner to clean the MUI cache by selecting the MUI cache on
the Registry pane. For more information about cleaning the
Registry, see
this topic.
