Archive for January, 2010


Maintaining Hard Drives

January 7, 2010

Hard drives are complex mechanical and electrical devices. With platters spinning at thousands of rotations per minute, they also generate heat and vibration. All of these factors make hard drives susceptible to failure.

Hard drive maintenance can be broken down into two distinct functions: checking the disk occasionally for failed clusters and keeping data organized on the drive so that it can be accessed quickly.

Individual clusters on hard drives sometimes go bad. There’s nothing you can do to prevent this from happening, so it’s important that you check occasionally for bad clusters on drives. The tools used to perform this checking are generally called error-checking utilities, although the terms for two older Microsoft tools – ScanDisk and CHKDSK (pronounced “CheckDisk”) – are often used. Microsoft calls the tool Error-Checking in Windows XP. Whatever the name of the utility, each does the same job: when the tool finds bad clusters, it puts the electronic equivalent of orange cones around them so that the system won’t try to place data in those bad clusters.
Most error checking tools do far more than just check for bad clusters. They go through all of the drive’s filenames, looking for invalid names and attempting to fix them. They look for clusters that have no filenames associated with them (these are known as lost chains) and erase them. From time to time, the underlying links between parent and child folders are lost, so a good error-checking tool checks every parent and child folder. With a folder such as C:\TEST\DATA, for example, they make sure that the folder DATA is properly associated with its parent folder, and that C:\TEST is properly associated with its child folder, C:\TEST\DATA.
To access error-checking on a Windows 2000 or Windows XP system, open My Computer, right-click the drive you want to check, and choose Properties to open the drive’s Properties dialog box. Select the tools tab and click the Check Now button to display the Check Disk Dialog box, which has two options. Check the box next to Automatically Fix File System Errors, but save the option to Scan For and Attempt Recovery of Bad Sectors  for times when you actually suspect a problem, because it takes a while on bigger hard drives.
Now that you know how to run Error-Checking, the next question is often, “How often do I run it?” A reasonable maintenance plan would include running it about once a week. Error-Checking is fast (unless you use the Scan For and Attempt Recovery of Bad Sectors option), and it’s a great tool for keeping your system in top shape.

Fragmentation of clusters can make your drive access times increase dramatically. It’s a good idea to defragment – or defrag – your drives as part of monthly maintenance. You access the defrag tool that runs with Windows 2000, XP, and Vista, called Disk Defragmenter, the same way you access Error-Checking – right-click a drive in My Computer and choose Properties – except you click the Defragment Now button on the Tools tab to open the Defragmenter.
Defragmentation is interesting to watch – once. From then on, schedule it to run late at night. You should defragment your drives about once a month, although you could run it every week, and if you run it every night, it takes only a few minutes. The longer you go between defrags, the longer it takes. If you don’t run Disk Defragmenter, your system will run slower. If you don’t run Error-Checking, you may lose data.

Disk Cleanup
Did you know that the average hard drive is full of trash? Not the junk you intentionally put in your hard drive like the 23,000 e-mail messages that you refuse to delete from your e-mail program. This kind of trash is all the files that you never see that Windows keeps for you. Here’s a few examples:

Files in the Recycle Bin
When you delete a file, it isn’t really deleted. It’s placed in the Recycle Bin in case you decide you need the file later.

Temporary Internet Files
When you go to a Website, Windows keeps copies of the graphics and other items so that the page will load more quickly the next time you access the page. You can see these files by opening the Internet Options applet on the Control Panel.

Downloaded Program Files
Your system always keeps a copy of any Java or ActiveX applets that it downloads. You can see these in the Internet Options applet. You’ll generally find only a few tiny files here.

Temporary Files
Many applications create temporary files that are supposed to be deleted when the application is closed. For one reason or another, these temporary files sometimes aren’t deleted. The location of these files varies with the version of Windows, but they always reside in a folder called TEMP.

Every hard drive will eventually become filled with lots of unnecessary trash. All versions of Windows tend to act erratically when the drives run out of unused space. Fortunately, all versions of Windows have a powerful tool called Disk Cleanup. You can access Disk Cleanup in all versions of Windows by choosing Start | Programs | Accessories | System Tools | Disk Cleanup.

Disk Cleanup gets rid of the four types of files just described (and a few others). Run Disk Cleanup once a month or so to keep plenty of space available on your hard drive.