When you install Win9x, you have the option to create an Emergency Boot Disk, a floppy with a minimal DOS bootup configuration on it. When you have internal problems with Windows, or if you want to re-install Windows, you can use this disk in the floppy to boot to DOS and repair or prepare the system as appropriate.
The Win95 EBD typically does NOT include the CDROM drivers, you can copy OAKCDROM.SYS and MSCDEX.EXE from the c:\Windows\Command directory to fix this and add the appropriate lines to Config.SYS and Autoexec.BAT on the floppy.
The Win98 EBD includes the CDROM drivers and a menu select option set.
To manually build a boot floppy in Win9x, first place a blank floppy in the A drive and format it with the Full and Copy System Files options. Then copy the following files:
c:\windows\himem.sys
c:\windows\emm.386.exe
c:\windows\command\fdisk.*
c:\windows\command\sys.*
c:\windows\command\format.*
c:\windows\command\oakcdrom.sys
c:\windows\command\mscdex.exe
c:\windows\command\xco*.*
c:\windows\command\edit*.*
to the root of the floppy, and use a text edittor to create a CONFIG.SYS and AUTOEXEC.BAT on the floppy to run the appropriate programs from the floppy vice the HD. If you have any added drive access interfaces (SCSI or a special-interface CDROM), copy those drivers as well and assign them in CONFIG.SYS or AUTOEXEC.BAT.
Plextor includes a Plextor Drive Manager utility, but I have never seen one of their drives fail to perform well with standard drivers, nor have I ever encountered a failure in a Plextor that wasn't due to things other than the drive. You may just have a bad 40-pin cable for it, or a bad MB adaptor connection...
There are websites (
www.bootdisk.com?) where you can download bootable floppy images and make a boot floppy easily.