Problems with Virtual Memory
It may sometimes happen that the system give ‘out of memory’ messages on trying to load a program, or give a message about Virtual memory space being low. Possible causes of this are:
The setting for maximum size of the page file is too low, or there is not enough disk space free to expand it to that size.
The page file has become corrupt, possibly at a bad shut-down. In the Virtual memory settings, set to have no page file, exit, shut down the machine and reboot. Delete PAGEFILE.SYS (on each drive if more than just C:), set the page file up again and reboot to bring it into use.
The page file has been put on a different drive without leaving a minimal amount on C:.
There is trouble with third party software. In particular, if the message happens at shutdown, suspect a problem with Symantec's Norton Live update, for which there is a fix posted HERE. If it happens at boot and the machine has an Intel chipset, the message may be caused by an early version (before version 2.1) of Intel's ‘Application Accelerator’. Uninstall this and then get an up-to-date version from Intel's site.
Possibly there is trouble with the drivers for IDE hard disks; in Device Manager, remove the IDE ATA/ATAPI controllers (main controller) and reboot for Plug and Play to start over.
With an NTFS file system, the permissions for the root directory of the drive where the page file is must give ‘Full Control’ to SYSTEM. If not, there is likely to be a message at boot that the system is ‘unable to create a page file’.