Why Clean Your Hard Drive?

If your system is running low on hard drive space, and you've been seeing the "Low Disk Space" warning message, you should take action to clean up the drive right away. Of course it's a problem if you have no room to store your music, photos, or videos on your hard drive, but low disk space can also adversely affect the performance of your computer.

When your operating system (Windows, Mac or Linux) runs out of RAM memory, it will try to create virtual memory by grabbing a chunk of hard drive space. If there is not enough space available, your applications may fail, or you may not be able to open large files. Even worse, when you run low on disk space, Windows will begin to delete System Restore points, or even switch off the System Restore feature entirely. (If you're not sure why that might be a problem, see my System Restore article.)

Another situation that necessitates a hard drive clean up is when you plan on selling, giving away or disposing of your old computer system. Since your system is filled with potentially sensitive information, you need to make sure your hard drive is clean before you get rid of it.

Emptying the Trash

One of the quickest ways to clean up your hard drive is to empty your Recycle Bin (Trash Bin for Mac users) frequently. You can do this by either clicking on the bin and then selecting to empty the bin, or you can use the Cleanup utility offered by Windows. Open My Computer, right-click a hard drive icon, select Properties, then click the Disk Cleanup button. This one action will allow you to free up a large amount of drive space that was occupied by deleted or unneeded files.

Removing Old Files

Old files also waste space on your hard drive. If you are running low on hard drive space, then you can clean up your hard drive by removing files that you no longer need or use. Windows users can try the Add/Remove Programs utility to "uninstall" unwanted programs. On Macs, AppZapper goes through your application folder, helping you to remove unneeded and unused software

.

Here are some other tips that should work on any system to reduce the load on your hard drive:

• Delete photos and movies you no longer need. These files can be HUGE sometimes.
• Open your media player and delete any music, video or podcasts you no longer need.
• Look through your Documents folder for old or unwanted word processor
  
  and spreadsheet files.
• Clean up your email folders - Inbox, Sent, Trash, Junk, etc.

Want to know my secret weapon when it comes to really cleaning up a hard drive? JdiskReport is a disc usage analyzer for Windows and Mac OS X systems that visually represents the space taken up by various files and folders on your hard drive. You can use it to find large files, overstuffed folders, and other hard-to-find junk. Mac users may also want to check out GrandPerspective, which does a similar job. If you run Ubuntu Linux, try the built-in Disk Usage Analyzer, or Baobab for other Linux/Gnome environments.

Reformatting Your Hard Drive

If you're going to get rid of your computer, especially if you plan on giving it to someone else to use, then you will want to make sure that all of your personal and business files have been removed from your hard drive.

Many people think that if you reformat your hard drive and then re-install the operating system, all of the data that was on the disk is permanently deleted. But that's not necessarily true. Formatting a drive will only remove the file access table (sometimes called the FAT) which tells the operating system where files are stored on the drive. It's true that a format and re-install will effectively overwrite and destroy some of the data on the drive, but you can't rely on that. A motivated person with data recovery tools could recover much of the data, even after a drive is formatted. If you have sensitive data on the hard drive, and you want to be sure it's REALLY clean, read the section below titled "Clean Hard Drive - The Ultimate Solution".

After the hard drive is reformatted, you will need to reinstall your operating system (and all necessary security patches) when you're done. Before starting, make sure you have a startup or recovery disc on hand to reinstall your operating system and desired programs after your reformat has been completed. You may also find it helpful to read my Reformat hard drive under XP article.

Clean Hard Drive - The Ultimate Solution

If you want to ensure that your hard drive is truly clean -- that none of your files can be recovered -- you can use software programs

like Acronis Drive Cleanser for Windows, or KillDisk for Windows and Linux machines. Mac user should check out this handy Erase Files from a Macintosh Hard Drive howto document. Basically, what these programs do is overwrite every piece of data on your hard drive with zeros. Now that's a clean hard drive.

Or is it? In some cases, skilled data forensics experts (think FBI, CIA, etc.) can recover data that's been overwritten by zeros as described above. I don't fully understand the physics involved, but apparently the "ghost of data past" can still lurk on the surface of a hard drive, even after overwriting. So if you're really paranoid, destroy the hard drive with a sledge hammer or run it through an industrial shredder, then purchase a shiny new hard drive for the computer you wish to sell or donate.