Temporary files (also called "temp files") usually have filenames that end with the extension .TMP. Though they share the same file extension, temporary files can be created by many different programs. This can make it difficult to figure out what program created a specific temp file, or even where the file came from.

Sometimes, the part of the filename before the extension will give you a clue as to where the file is from. For example, if the filename is 2006_annual_report.tmp, the file might be a Word document or Excel spreadsheet that was named "2006 annual report." Other times, the location of a temp file may help you determine what program created the file. For example, if you find a temp file in a folder named "Temporary Files" within the main folder of a certain application, the temporary file most likely belongs to that application.

Why are temp files created?

Programs create temporary files primarily for backup purposes. Many programs, such as those included with Microsoft Office, will save a temporary version of a file every few minutes while the original file is open. Then if you have not saved the file and the program unexpectedly crashes or the computer shuts down, there will be a temporary file that was recently saved. Temp files are typically deleted automatically when the program is closed normally, but if the program quits unexpectedly, the temp files are not deleted.

However, some temp files are left behind even when a program is quit correctly. This may be due to programming errors that cause temporary files to not be correctly disposed of when an application is quit. These files can accumulate on your hard drive without you even noticing.

Finally, Web browsers, such as Internet Explorer, create "Temporary Internet Files" to store user data, including cookies, images from visited Web pages, and the user's browsing history.

How do I delete temp files?

If you plan on manually removing specific temp files, first make sure the files you want to delete are actually temporary files and that you do not need them for any reason. Once you have verified that they are not needed or are duplicates of other files, simply move the files to the Recycle Bin (Windows) or the Trash (Mac) and empty the trash.

If you want to delete many temp files at once, several programs are available that will automate the process for you. These programs can search your hard disk for temp files and remove the ones you don't need, saving hard disk space. Some examples of Windows utilities include:

• TFCLEANUP
• 4Diskclean
• Easy Erase File Cleaner
• CleanIt
• G-Lock Temp Cleaner
• Delete History Free
• Softes Windows Cleaner
• PARC Shredator

NOTE: If you want to delete Temporary Internet Files in Windows, follow these instructions.