In Windows XP, when you added more memory to your computer, you had to manually go and increase the size of your paging file to correctly match the amount of memory in your computer. Windows Vista does away with this by automatically setting the optimal size for the paging file, even after you add more memory to your computer.
For instance, if you had a computer with 1GB of memory, your paging file would be roughly 1300mb, but if you add another 1GB of memory to your computer to make a total of 2GB, now when you look at the paging file, it will have automatically increased:
You can turn this setting on and off by right-clicking the Computer icon, clicking the Advanced System Settings link, then clicking the Settings button under Performance:
Click the Advanced tab, and you should see the current size of the paging file as in the first screenshot. Click the Change button, and you’ll finally see the checkbox to “Automatically manage paging file size for all drives”
You can uncheck this box and set the paging file manually if you’d like. If you have a number of fast drives in your system, you could configure the system for optimal performance by using a faster drive for the paging file, but I’d recommend just leaving the default setting on in most cases.
