Old DOS disk works on Windows, but it’s risky.

Question: Can an older DOS boot disk be used on a computer that runs Windows 95 as the operating system?

Answer: There was no clear consensus among my fellow workers on this matter. Sure, you can boot the machine with an older version of MS-DOS. The question is: Do you want to? –Dan M.

I liken it to playing hockey with a clay pigeon in a stadium of shotgun-toting spectators. It’s dangerous.

A DOS boot disk will boot a Windows 95 machine, but when it reads and displays a long filename it will be shortened to the old 8.3 file format. That’s eight characters, a period, and a three-character file format extension, like “auntedna.doc” or “hairylip.gif”.

Under Windows 95, filenames can contain up to 255 characters, including spaces, except for the following punctuation characters: / : * ? ” < > |.

So an older version of DOS would read a long Windows 95 filename like “Aunt Edna smooching Andy at Christmas.jpg” and shorten it to “aunted~1.doc”. More than one filename starting with the words “Aunt Edna” (God forbid) would be indistinguishable from each other because they would be shortened to the 8.3 format.

The problem gets even nastier if your version of Windows 95 uses a FAT32 volume. What the heck is that, you might ask in trepidation, fearing more obscure references to my hairy-lipped aunt? FAT is short for File Allocation Table. That’s a kind of index the operating system uses to locate files on a disk. A FAT32 volume is a 32-bit FAT that allows storage of pathnames greater that 256 characters in length and supports hard drives larger than 2 Gigabytes.

Your system uses FAT32 if your version of Windows 95 is 4.00.950b or 4.00.950c. It’s an upgrade that only comes with new PCs. It was fully integrated into Windows 98 when it was released in 1998. To check your version, right-click on My Computer and select Properties.

Another word of warning comes from Michael Hanley, a senior help-desk technician at Microsoft Canada. “If you have a drive formatted with FAT 32, you will be able to boot up from the old DOS floppy, but not be able to see the drive.” To read that drive with a bootable floppy, you’ll need to make an emergency recovery disk with a system that has one of the newer versions of Windows 95 installed. “The disk can be made by going to Control Panel, Add/Remove Programs, Startup disk, and then click create disk,” said Hanley.

To read more information about emergency boot disks, click Start > Help, type boot disk and click the Display button on your Windows 95 system.