Windows 7 : General Maintenance Tools (part 3) - Checking Your Disks for Errors & Optimizing Disk Performance

3. Checking Your Disks for Errors

Your primary disk is one of the most-used pieces of hardware on your computer. Your computer is constantly reading and writing data. If it experiences the slightest hiccup, the wrong data can be written to parts of the disk. If a particular sector or cluster on a disk is damaged or otherwise cannot be written to, your computer will experience problems whenever it tries to read or write data to this sector or cluster. Though Windows 7 and hardware controllers on the disk drives themselves both do a good job of correcting problems, neither one can correct all disk problems. To keep your computer’s disks running optimally, you need to check your computer’s disks periodically for errors and correct any errors found.

You can check disk drives for errors and correct any errors found by following these steps:

1. Click Start→Computer. Under Hard Disk Drives, right-click the drive you want to check and then select Properties.

2. On the Tools tab, click Check Now. This displays the Check Disk dialog box, shown in Figure 7.

Figure 7. Checking your disk for errors

1. To check for errors and attempt to resolve them, select either or both of the following options, and then click Start:

   Automatically fix file system errors

   When this is selected, Windows 7 fixes any filesystem errors it finds.

   Scan for and attempt recovery of bad sectors

   When this is selected, Windows 7 checks for bad sectors and attempts to recover readable information from them.

2. With the primary disk or other disks that are in use, Check Disk displays a prompt that asks whether you want to schedule the disk to be checked the next time you restart the system. Click Yes to schedule this check.

3. When Check Disk finishes analyzing and repairing the disk, click OK.

4. Optimizing Disk Performance

Another problem that causes disk drives to perform poorly is fragmentation. Fragmentation occurs when a file can’t be written to a single contiguous area on the disk, and the operating system often must write a single file to several smaller areas on the disk. Having to seek different parts of the disk slows down not only the write process, but also the read process. Because fragmentation is the number-one cause of disk performance problems (second only to disks being packed with too much information), Windows 7 uses Disk Defragmenter to defragment disks automatically.

Windows 7 runs Disk Defragmenter automatically at 1:00 a.m. every Wednesday by default. As long as the computer is on at the scheduled runtime, automatic defragmentation will occur. You can cancel automatic defragmentation or modify the defragmentation schedule by following these steps:

1. Click Start and then click Computer. Under Hard Disk Drives, right-click a drive and then select Properties.

2. On the Tools tab, click Defragment Now. This displays the Disk Defragmenter dialog box, shown in Figure 8.

3. Click Configure schedule and the Modify Schedule dialog box, shown in Figure 9, appears.

4. To cancel automated defragmentation, clear “Run on a schedule” and click OK, and then click Close.

5. To modify the defragmentation schedule, ensure that “Run on a schedule” is selected and then choose the desired settings. For example, you might want to schedule automatic defragmentation to occur every Thursday at 9:00 a.m. during your weekly staff meeting. Click OK, and then click Close.

6. Click OK.

Figure 8. Viewing the Disk Defragmenter configuration

NOTE

Windows 7 will defragment your disks only if the computer is on, meaning that the computer isn’t sleeping or powered off. To ensure that your computer’s disks are defragmented periodically, you’ll want to use a time when you know you’ll be in the office or at home on the computer. Because of performance improvements to Windows 7, you might not even notice defragmentation is running. Why? Well, unlike Windows XP and other earlier releases of Windows, Windows 7 gives whatever programs you are running priority over background housekeeping tasks such as disk defragmentation.

When you access Disk Defragmenter, the last runtime and next runtime are listed. If your computer hasn’t been automatically defragmented in several weeks or months, you can defragment a disk manually by completing the following steps:

1. Click Start→Computer. Under Hard Disk Drives, right-click a drive and then select Properties.

2. On the Tools tab, click Defragment Now.

3. In the Disk Defragmenter dialog box, click “Defragment disk.”

4. Defragmentation can take several hours. You can select a disk that’s being defragmented, then click “Stop operation” at any time to stop defragmentation.

Figure 9. Modifying the run schedule