A paging file in Windows is an area of the hard-disc that the Windows operating system reserves for operations that it would otherwise carry out using the system’s RAM. The actual amount of this area that Windows uses depends upon 2 major factors: How much of the processor’s capability you are currently using, combined with how many programs you have running, and how much RAM you have fitted to your computer’s motherboard.

With a 32-bit operating system there’s probably always going to be at least a tiny part of the reserved space used, as the maximum amount of RAM that a 32-bit operating system can see at any given point is 4 gigabytes. In practice, owing to operating tolerances as well as taking into account various system hardware caches, the actual amount of RAM that a 32-bit operating system will recognise is around 3.5 gigabytes. – It’s a fair bit of RAM, and enough for most applications, but not many computers running a 32-bit operating system have more than around 2GB RAM. With a 64-bit operating system you can fit up to several exabytes of RAM, so therefore the more RAM you have fitted the less the paging file is used, to a certain extent anyway.

Having said all that, though, I do know that people have turned off their paging file completely whilst running XP Pro 32-bit with a gigabyte of RAM, and as far as I am aware their computer ran something like normally. I don’t suggest you try it for yourself, though.

So why would you want to adjust the size of your paging file? To be honest the only reason I can think of, other than trying your computer out to see if it runs without a paging file, or changing its size following installation of more RAM, (which isn’t compulsory.) is in a case where you’re running so low on disc space that Windows won’t work properly; and you need just that little bit extra before you can get the C: drive to a state in which you can fit a larger hard-drive and all that it entails without Windows going tits-up somewhere in the process. – Therefore you cut down the System Restore area and the paging file allocation on C: to make that bit of extra room, cross your fingers and everything else, pray if you’re religious, and begin.

Without going too far off track; here’s how to get to the necessary adjustments that Microsoft have cleverly buried in XP: -

Right-click on the “My Computer”icon and click “Properties”. In the Performance section at the top of the dialogue box, click Settings. Click the Advanced tab, and click the Change button in the Virtual memory section.

…And you’ll see something very much like this: -

Normally, as you’ll note from the pic, I leave it to Windows to decide the size of it: Windows knows what it’s doing – more or less – and has a rough idea what size paging file it needs. My C: drive on this particular computer is about 79.5 GB in size, and is partitioned off from the rest of the drive. Windows uses a few MBs of that for the paging file and I don’t really worry about it that much if at all. I only have a paging file on C: drive. It’s set to “No paging file” for all the other drives; which means that it’s turned off on all other drives.

You may want to set the size of your paging file however. Indeed it may already be set to some limit. If you get problems with paging file size then you might like to set it as I have done; then if Windows has issues with its current size it’ll pop up a notice on-screen telling you that it’s enlarging the paging file, and do so.

To set your paging file within custom parameters; select “Custom size” by putting a . in the appropriate radio button, and typing in the size you want. There are all kinds of advisories that tell you what size you should set it to; some of which have conflicting advice. – Which is why I let the operating system handle it.

If you select the drive letter by highlighting it, you can set a paging file size for most drives; other than removable drives for obvious reasons. I’ve tried putting the paging file on other drives than C:, on other drives as well as C:, even partitioning a separate drive specially for the paging file alone: In my experience nothing seems to be better than having it on C: drive only and letting Windows manage its size.

Do you have different experiences? If so then please do comment.

- Other than that; that just about rounds it off.