Thank to everybody answer the topic I've finally have my first DVD with 3 os on and working And a special thank's to the author of http://www.ultimatebootcd.com/ (I don't remember in which topic i take that but it work, i give the autoexec.bat and config.sys ) Autoexec.bat @ECHO OFF set EXPAND=YES SET DIRCMD=/O:N cls set temp=c:\ set tmp=c:\ path=a:\ LH MSCDEX.EXE /D:oemcd001 /L:D echo. :AUTOSETUP set CDROM=FOO23 FINDCD.EXE if "%CDROM%"=="FOO23" goto NOCDROM path=a:\;%CDROM%\ %CDROM% cd \SETUP\98SE\WIN98 echo. OEMSETUP.EXE /K "/IE /NF" goto QUIT :NOCDROM echo. echo The Windows 98 Setup files were not found. echo. :QUIT Config.sys device=himem.sys /testmem:off device=oakcdrom.sys /D:oemcd001 device=btdosm.sys device=flashpt.sys device=btcdrom.sys /D:oemcd001 device=aspi2dos.sys device=aspi8dos.sys device=aspi4dos.sys device=aspi8u2.sys device=aspicd.sys /D:oemcd001 files=60 buffers=20 dos=high,umb stacks=9,256 lastdrive=z Thank