Some things to try:

• Remove the EMM386 NOEMS option, if it is used without the NOVCPI option.
• Remove the EMM386 FRAME=NONE option, if you use it.
• Configure EMM386 with both the NOEMS and NOVCPI options.
• Convert the DEVICEHIGH statements in your CONFIG.SYS to DEVICE statements, and remove the LH (Load High) commands from your AUTOEXEC.BAT.
• Run in a MS-Windows DOS box.
• Run with HIMEM.SYS alone (No EMM386).
• Set the environment variable DOS4GVM equal to 1, so that the virtual memory manager uses the default values (SET DOS4GVM=1).
• Remove SMARTDRV and other memory intensive programs from your AUTOEXEC.BAT and CONFIG.SYS.
• Try the below AUTOEXEC.BAT and CONFIG.SYS files. Make sure you change C:\FLOAT directory to your tool directory.

If these work try to add the lines that you were using one at a time to determine the problem.

*******************************
config.sys 
************************************ 
DEVICE=C:\DOS\HIMEM.SYS
DEVICE=C:\WINDOWS\EMM386.EXE 
NOEMS NOVCPI 
DOS=HIGH,UMB 
SHELL=C:\DOS\COMMAND.COM BUFFERS=30
FILES=30 
FCBS=4,0 
LASTDRIVE=Z 
STACKS=9,256 
******************************* 
autoexec.bat
******************************* 
SET DOS4GVM=1 
SET DOS4G=quiet 
SET C_DIR=C:\FLOAT
PROMPT=$P$G 
PATH C:\DOS;C:\WINDOWS;C:\FLOAT
*******************************