就是xmsdsk建不了虚拟磁盘
AUTOEXEC.BAT内容如下:
@ECHO OFF
set EXPAND=YES
SET DIRCMD=/O:N
set LglDrv=27 * 26 Z 25 Y 24 X 23 W 22 V 21 U 20 T 19 S 18 R 17 Q 16 P 15
set LglDrv=%LglDrv% O 14 N 13 M 12 L 11 K 10 J 9 I 8 H 7 G 6 F 5 E 4 D 3 C
cls
xmsdsk 8192 %ramd%: /y/t
set temp=c:\
set tmp=c:\
set path=%RAMD%:\;a:\;a:\vc;a:\reg;%CDROM%:\
copy command.com %RAMD%:\ > NUL
set comspec=%RAMD%:\command.com
copy extract.exe %RAMD%:\ > NUL
copy ebd.cab %RAMD%:\ > NUL

%RAMD%:\extract /y /e /l %RAMD%: %RAMD%:\ebd.cab > NUL

echo The diagnostic tools were successfully loaded to drive %RAMD%.
echo.
LH %ramd%:\doskey.com
LH %ramd%:\ctmouse.exe
LH %ramd%:\mousclip.exe/m
LH %ramd%:\Mscdex.exe/d:mscd001
LH %ramd%:\doslfn.com/c+
LH smartdrv.exe 10240 10240

问题就出在 xmsdsk 8192 %ramd%: /y/t 这一行上， %ramd% 变量还没定义。

在xmsdsk 8192 %ramd%: /y/t之前有加过call setramd.bat %LglDrv%
setramd.bat内容:
@echo off
set RAMD=
set CDROM=

echo.
echo Preparing to start your computer.
echo This may take a few minutes. Please wait...
echo.

a:\findramd

if errorlevel 255 goto no_ramdrive

if not errorlevel 3 goto no_ramdrive

goto do_shift

:loop
if errorlevel %1 goto no_shift

:do_shift
set cdrom=%2
shift
shift
if not %1*==* goto loop
goto no_ramdrive

:no_shift
set ramd=%2

if "%RAMD%"=="C" goto c_drive

goto success

:c_drive
echo Windows 98 has detected that drive C does not contain a valid FAT or
echo FAT32 partition. There are several possible causes.
echo.
echo 1. The drive may need to be partitioned. To create a partition on the drive,
echo run FDISK from the MS-DOS command prompt.
echo.
echo 2. You may be using third-party disk-partitioning software. If you are using
echo this type of software, remove the Emergency Boot Disk and restart your
echo computer. Then, follow the on-screen instructions to start your computer from
echo a floppy disk.
echo .
echo 3. Some viruses also cause your drive C to not register. You can use a virus
echo scanning program to check your computer for viruses.
echo.
goto success

:no_ramdrive
echo The Windows 98 startup disk could not create a temporary drive for the
echo diagnostic tools. This may be because this computer has less than the
echo minimum required extended memory.
echo.
:success
但提示The Windows 98 startup disk could not create a temporary drive for the
echo diagnostic tools. This may be because this computer has less than the
echo minimum required extended memory.