From: http://www.computerhope.com/issues/ch000397.htm Program too big to fit into memory
 

Issue

Program too big to fit into memory.

Cause

This issue can be caused by any of the below possibilities.
  1. Partition incompatibility
  2. BIOS update issue
  3. Autoexec.bat or config.sys error
  4. Computer Virus
  5. Software issue

Solution

Partition incompatibility
When installing an operating system and encountering the error "Program too big to fit into memory", ensure that it is being installed onto a partition or FAT that is supported by the operating system.
MS-DOS - Can only be installed on a FAT12 or FAT16 partition, not NTFS or FAT32.
Windows 95 OSR1 - Can only be installed on FAT16.
Windows 95 OSR2 - Can only be installed on FAT16 or FAT32.
Windows NT 4.0 - Can only be installed on a FAT16 or NTFS partition.
BIOS update issue
If you are encountering this issue when attempting to upgrade the computer BIOS, ensure that the file downloaded from the respected manufacturer page is not on the floppy diskette (unless otherwise instructed). Many times the compressed BIOS file, if placed on the same diskette extracted to, will run out of available disk space and cause this error. The file downloaded must be saved onto the hard drive and then extracted to the floppy diskette.
If this does not resolve your issue, it is recommended you contact the computer or motherboard manufacturer for additional recommendations and help on successfully running the BIOS update.
Autoexec.bat or config.sys error
If you are experiencing the error "Program too big to fit into memory" when booting the computer it is likely that a line or TSR loading in the autoexec.bat and config.sys is causing the issue.
It is recommended that users running Windows 3.x, Windows 95, Windows 98 that you verify the emm386.exe and himem.sys are being loaded. If this does not resolve the issue, attempt to temporarily remark or remove any lines that may not be needed from the autoexec.bat or config.sys.
Windows 95 and Windows 98 users may also want to consider temporarily renaming the autoexec.bat and config.sys. To do this follow the below steps:
  1. Click Start, Settings, Shutdown, and Restart the computer in MS-DOS mode.
  2. At the MS-DOS prompt type:

    cd\ <press enter>
    ren autoexec.bat autoexec.ch <press enter>
    ren config.sys config.ch <press enter>

    Once the above files have been renamed, reboot the computer to determine if the issue has been resolved.
Computer virus
Verify the computer has the latest virus definition or dat update. Computer viruses can cause this issue or other memory related issues.
Software issue
If you are encountering this issue when attempting to run a software program or game and the above recommendation do not apply or resolve your issue, verify with the software vendor or developer if the program has any available fixes, patches, or updates for the program.