The page files are one or more areas of your hard disks that Windows XP reserves as virtual memory. To put it simply, these reserved areas are used to contain any data that may spill over from your main memory.

Virtual memory is accessed by Windows just like physical memory, but is many times slower, due to the much slower speed of hard drive data transfer as compared to RAM. Windows XP actually uses the Page files continuously, regardless of the amount of free memory on your system, so optimizing these files can have a positive effect on the performance of your computer.

To optimize the page file(s), there are a few options you can consider.

Page File Placement:

Since Page files require intermittent disk access to write and retrieve information, putting them on the same drive as the operating system can compromise the performance of both. Of course, since most systems contain only a single hard drive, this is not usually something that can be changed. If your system contains more than one hard disk, consider placing a page file on the the non-OS disk and removing the one on the OS-disk containing the Windows files.

To do this: Right click on 'my computer' and select 'properties' then the 'advanced' tab. In the 'performance' section, click 'settings' then select the 'advanced' tab. In the 'virtual memory' section, click 'change.' From here you can choose individual drives and customize the size of the paging files you wish to create.

Page File Size:

By default, page files are created with a starting size and a maximum size. These values allow Windows to resize the paging file as system demand grows. It is more efficient to set an identical starting and maximum value so that no resources are wasted resizing the file.

To do this, choose 'custom size' for each page file and set the initial and maximum sizes to the same number.

As for what size to set them at, the best bet is to leave them at, or slightly below the default 'maximum' setting the system assigned, with a ceiling of 1GB. This is the amount of space that is reserved for the file, regardless of its current size. If you are creating multiple page files, split the amount between them.