In Windows, what is a swap file?

A swap file, also called a page file, is an area on the hard drive used for temporary storage of information. Windows uses the swap file to improve performance. A computer normally uses primary memory, or RAM, to store information used for current operations, but the swap file serves as additional memory available to hold additional data.

Note: Microsoft recommends that you allow Windows to manage the Virtual Memory settings for you (i.e., leave the default setting as is). Only experienced users should change this setting, as it can adversely affect system performance.

Also note that you can manually move the location of the swap file to a different drive. In some situations, this can be advantageous. If you have a drive with more free space or a faster access time, you may improve performance by moving the swap file to this drive.

Windows 2000, XP, and Vista allow you to set up swap files for each drive on your system. In these versions of the Windows operating system, the swap file is dynamic and hidden.

Windows Vista

To view your current swap file information in Windows Vista:

1. From the Start menu, right-click My Computer, and then select Properties.
   
   
2. From the Tasks menu, select Advanced system settings.
   
   
3. In the dialog box that opens, click the Advanced tab. Under the "Performance" section, select Settings... .
   
   
4. In the Performance Options dialog box, select the Advanced tab.
   
   
5. Click Change... . The swap file information is listed at the bottom.

Windows 2000 and XP

The name of the Windows 2000 and XP swap file is pagefile.sys, located in the root directory. The swap file is dynamic, changing size depending on system conditions. If you run several applications at once, the swap file will grow to accommodate the additional information required to run each application smoothly. This is a hidden file, so you will have to change your folder view setting to be able to see the file.

To view your current swap file information in Windows 2000 or XP:

1. Right-click My Computer, and then select Properties.
   
   
2. Select the Advanced tab.
   
   
3. Under "Performance", click Settings.
   
   
4. Select the Advanced tab. Information about your swap file is listed under "Virtual memory".

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