I had a search around and found an article of someone mentioning they got MS-DOS installation on bootable cd.

I am wondering if anyone who has done this to let me know how they manage to do this?

Best burning program is Nero Burning ROM. It specifies two types of bootable CD-ROMs:

1. CD-ROM (Boot)
2. CD-ROM (EFI Boot)

I guess if I have the floppy disks then the boot image data is easy to get. However if I only backed up my MS-DOS 6.2 files of the disks then I won't have the boot image data. If the latter is the case, can Nero still do sometime to make it boot up (like grab the Windows 98SE boot image instead). Then we have unseen problems such as whether MS-DOS setup/install requires data from A:\ drive. Hmm...