The computer prompts "virtual memory is insufficient" solution

Many of my friends' computer systems are Windows XP. Sometimes, when using, there are obviously not many programs, but there are often system prompts for insufficient virtual memory. How to solve these problems?
1, anti-virus Some viruses will take up a lot of memory space, resulting in the system has insufficient memory. Hurry up to kill the virus, upgrade the virus database, and then do the anti-virus measures.
2, reasonable setting of virtual memory virtual memory settings can also lead to memory shortages. In general, the virtual memory size is twice the size of the physical memory. If it is set too small, it will affect the normal operation of the system program.
Re-adjust the virtual memory size. Take Windows XP as an example. Right click on “My Computer", select “Properties", then on the “Advanced" tab, click “Settings in the performance box. ; button, switch to the "Advanced" tab, then click the "Change" button in the "Virtual Memory" box, then reset the virtual memory size, restart the system after the completion.
3, adjust the system space virtual memory file is placed in the system disk by default, such as WindowsXP virtual memory file named "pagefile.sys", if the remaining space of the system disk is too small, it will lead to the problem of insufficient virtual memory .
The system disk must retain at least 300MB of free space, of course, this value depends on the actual needs of users. Users should try not to install various application software on the system disk. It should ensure that there is enough space for virtual memory files to use, and it is better to place virtual memory files on non-system disks.
4, modify system user permissions Based on the NT kernel Windows system startup, system users will create virtual memory files for the system. Some users use the NTFS file system for system security, but they cancel the system user's permission to write ” and “ modify & rdquo; so that you cannot create virtual memory files for the system when running large programs. There will also be a problem of insufficient memory.
The problem is solved very well, as long as the system user is re-assigned to ” and “ modify & rdquo; permissions, but this is limited to users using the NTFS file system.