Windows NT, 2000, XP and Vista

The Windows New Technology based file system checking utility is called chkdsk - an abbreviation for Check Disk.

From Windows

There is a GUI wrapper for chkdsk, but it doesn't really give us the details and options we need. To run chkdsk:

• Click Start and Run, or hit your Windows key + R
• type cmdand hit enter
• type chkdsk c:

Chkdsk will run in read-only mode by default and will only report errors, not fix them. It is possible for chkdsk to falsely report errors in this mode, because the volume it is checking may be modified during the procedure by another application. For chkdsk to make any repairs, it needs to dismount the volume to ensure no other software can interfere. You can run chkdsk in fix mode with the following command

• chkdsk c: /f

Your boot volume (where Windows resides, usually c: ) cannot be dismounted Windows is running, or the system would crash, so instead chkdsk displays the following message:

Choose Yes and then reboot the system. If you specify a non-boot volume, say d: for example, chkdsk is able to lock the drive while Windows is running. If you have any open files (this includes programs), or are browsing that volume, the following message is displayed:

Selecting Yes will force a dismount, which will close any files in a non-graceful manner (files are slammed shut and programs will crash), so close anything that is running off, or using that volume. If there is a page file or other system file on that volume, you will not be able to dismount it. If you choose No, chkdsk will offer you the next boot option.

By default, chkdsk will perform a number of important tests related to the structure, layout and consistency of files in the volume, but it does not check empty space for errors, or check for bad sectors. To do this, use the following command

• chkdsk c: /r

This will take a lot longer, but is a good idea if your hard disk drive has known defects. If it happens to pick up any bad sectors, run a HDD diagnostic (help available here). This ensures that the bad sectors are properly recorded in the HDD firmware, so they will never be used again; otherwise you must run chksk c: /r every time you format the drive.

From the Installation disc

Sometimes you cannot boot into Windows to perform a chkdsk (usually when you need to do it most).

To access chkdsk, you need to enter the Recovery Console. This refers to Windows 2000 and XP. Vista has not yet been confirmed...

• Boot from your installation CD
• When first prompted, hit R to enter the Recovery Console
• Select your boot volume (usually 1)
• Enter the Administrator password. If you're using Windows XP Home or you didn't set one, just enter.

The chkdsk options are slightly different from the Recovery Console. To automatically fix errors, use the following command:

• chkdsk c: /m

Windows 95, 98 & ME

Nothing yet!