Q I have found a file in the root directory of my network server and I was wondering whether you could shed some light on the nature of it. The file name is pagefile.sys and it's 190MB in size. It is taking up a lot of space, so I'd like to know: 1. What is it and what is it used for? 2. Can I safely delete it?

A We've all been there: you find a mysterious file soaking up disk space on a jam-packed drive and your finger hovers over the <Delete> key. Should you or shouldn't you?

The usual Help Screen advice in situations like this is to move the mystery file to a safe location, run the system for a week or two, and - if everything appears to be functioning normally - delete the file. But don't try this with pagefile.sys!

Caption: On a Windows NT system, you may be able to recover some disk space by reducing the size of the virtual memory paging file

Pagefile.sys is a critical component of the Windows NT virtual memory system and operates in concert with your system's physical memory. You shouldn't attempt to delete this file at the operating system level, but if disk space is at a premium you may be able to reduce its size. To do this, open the System Control Panel and, on the Performance tab, click Change. In the resulting dialogue box, you can reduce (or increase) the initial and maximum sizes of the paging file on the highlighted drive. You may need to experiment a little to find the optimum values for these settings, but, as a general rule, try to ensure that the Initial Size value is equal to or greater than Windows' Recommended value for the Total Paging File Size for All Drives. (Note: You will need Administrator privileges to change the paging file size.)