Paging is normally enabled by default, its size is controlled by the operating system. If for some reason the swap space on your computer was disabled, to enable, open "start" - "control Panel" - "System" - "Advanced".
In the section "Performance" click "Settings". A window will open, select the "Advanced" tab. In the new window you will need section "Virtual memory" - find it and click "Edit".
A window will open "Virtual memory", select in the menu "the Size for choice systems". In this case, Windows will select the required size of the paging file (virtual memory). You can set the desired size yourself, please select "custom size". Typically, the size of the paging file is selected equal to twice the size of RAM. So if your computer has 1024 MB of RAM, the minimum pagefile size should be 2048 MB. The maximum may be equal to three times the size of RAM.
Place the paging file on a different drive or partition where the OS is installed, it will increase the performance of your computer. To move the paging file pagefile.sys to another disk, select "the Size for choice systems", and then specify the list of disks need a drive or partition. Save the changes. Windows will warn you that the new settings will be introduced only after a system reboot. Restart the computer again, open the window "Virtual memory" and check which disk is the paging file.
The paging file is hidden and in order to see it, enable show hidden files. Open any drive or folder, select: "Tools" - "folder options". Under "Hidden files and folders" select "Show hidden files and folders". Now you will be able to see the file pagefile.sys.
If the RAM of your computer is several gigabytes, paging can be switched off completely, this has a positive effect on the speed of the system. While you will be able to turn it on. Vista users disable the paging should not be.