Why is cleanup needed?

There are various ways that Windows systems accumulate unneeded files. The operating system and other software make use of a variety of temporary files that are created in several systems folders. These folders include several Temp folders. Normally, these folders are located in \Windows\Temp and \Documents and Settings\{User}\Local Settings\Temp. (This latter folder is more conveniently written as the environment variable %TEMP%.) Sometimes there may also be a Temp folder in the root (usually C:) directory or other locations as well. Some programs are better than others at cleaning up after themselves but many programs (including Microsoft Office) leave a lot of litter.

Another source of large numbers of temporary files is the Internet, Every time a page is downloaded from the Web, all the constituent files that go to make up that page are stored in a cache folder. For Internet Explorer the folder is called “Temporary Internet Files”.. (Other browsers such as Firefox and Chrome have their own location in database form.) A single Web page may have dozens of associated files. Every banner, button or other graphic requires a separate file. Thus it is very easy to accumulate many megabytes of files. At some point your Internet surfing will be slowed as the browser hunts through all the cached pages. Surfing the Internet also leads to the accumulation of “cookies”.

The various kinds of temporary files can be created in very large numbers and require a substantial chunk of space. Before hard drive capacity grew to today's huge sizes, efficient use of limited space on the hard disk was a paramount concern. While that particular issue is much diminished today, cleaning up unnecessary files is still important for preventing slow-downs in operation. The more files that the system has to search through in carrying out a function, the slower it will be. For example, anti-virus scans, defragmenting, or backing up may take considerably longer. In extreme cases, too many temporary files can even cause system crashes.

Another area of the operating system that may need maintenance is the Registry. The Registry is constantly being accessed while your computer is in use. Practically every change that is made to the system affects the Registry. Over time the Registry acquires many useless entries and grows in size. Installing and then removing software almost invariably leaves junk behind in the Registry even when using the recommended uninstallation procedure. The more entries in the Registry, the longer it takes for the system to find things and over-all operation may be slowed. More recent Windows systems have a lessened tendency to problems in this area but proper Registry maintenance may still be useful in Windows XP for those who make many system changes and program installations. Windows Vista/7 systems are rarely likely to need this type of maintenance, however.

Disk Cleanup tool

Windows comes with a system tool called Disk Cleanup that can help keep the system clean. The tool can be accessed in several ways. In Windows XP, it is listed in the Start-All Programs- Accessories-System tools group. It can also be opened by right-clicking on a drive icon in (My) Computer, choosing "Properties" from the context menu, and clicking the button "Disk cleanup" on the properties sheet. Another and perhaps quicker way to open the accessory is to enter "cleanmgr" into the Run line or the Search box of the Start menu. This accessory provides a unified interface for managing various temporary files and the Recycle Bin. Using it is discussed in more detail on another page. As discussed in that reference, the Disk Cleanup utility has some limitations. However, it may provide an adequate method for managing temporary files for those who do not run many programs. More active PC users may prefer more thorough methods as discussed in sections below.

Clean the Temp Files

Each user account has a folder where programs put temporary files. The easiest way to reach the folder is to use the environment variable %TEMP%. Some programs also use a folder \Windows\Temp. Although these temporary files can be deleted by going directly to the folders in Windows Explorer, selecting all the files, and doing a delete, the process is often interrupted because some file is in use and is locked. A better method is to use the command line. Entering the command del /f /q /s %TEMP%\* %windir%\temp\* will clean up all unlocked files in the two temp folders. If you prefer, I have written a script for this chore. Files that are in use or locked will not be removed.

Clean Internet Explorer 8 Cache (Temporary Internet Files)

Internet Explorer (IE) stores Web pages that you view in a folder named "Temporary Internet Files" that is normally kept in the location \Documents and Settings\{User}\Local Settings\. The purpose is to help speed up browsing if you return to a page. As mentioned above, these files can accumulate and periodically deleting them can sometimes actually speed browsing. Deletion can be done in Disk Cleanup or in the settings for Internet Explorer. Various other kinds of data are also kept. These records can be deleted as indicated in the figure on the left. This dialog box is reached through "Internet Options" by clicking the "Delete" button in the "Browsing History" section under the "General" tab.. Deleting Temporary Internet Files by this method does not completely clean the folder with that name. In addition to material from pages downloaded from the Web, the folder also contains Internet cookie pointer files involved in the rather convoluted system used by Microsoft.

My personal choice for keeping the Internet cache from growing too big is to use the setting that clears the cache whenever IE is closed. Open the Internet Options dialog box and click the tab "Advanced". Scroll to the section "Security" and check "Empty Temporary Internet Files folder when browser is closed". Note that not all files are deleted by this method. Cookie pointers and certain other files are retained. The figure below illustrates the setting.

Configure the Recycle Bin

Windows XP

The Recycle Bin is easily emptied either directly or by using the Disk Cleanup utility. Even so, many PC users forget to periodically empty the deleted files and accumulate large numbers. If the Recycle Bin becomes too large, it can slow the system. One solution is to limit the size of the Recycle Bin. By default, the size is set at 10% of the hard drive, which is excessive on today's large drives. A more practical limit to the size is something like 1%. To change the amount of space that is set aside for the deleted files in Windows XP, right-click the Recycle Bin and open "Properties". The figure on the left illustrates. Move the slider shown on the properties sheet to decrease the amount of disk space that is reserved for storing deleted items.

Cleaning the Registry

It is my personal opinion that the average PC user should forget about Registry cleaning. My reasoning is given in this article. Experienced PC users who are interested in Registry cleaning will find information about the programs that are available for this purpose at this link.

Software utilities

There are many commercial programs that claim to clean up Windows. Frankly, most would be a waste of money if you bought them. A freeware cleanup program that is highly regarded is CCleaner. This program can be quite aggressive in its cleaning so be sure to check all the settings before you use it.

Use any cleanup program with care and back up your system first.