Formatting 720K Floppies

The secret to formatting a diskette to 720K under Windows 2000/XP is simple: you have to convert an HD diskette to a DD diskette. To do this, cover the hole that specifies that the disk is HD with a piece of scotch tape:
Converting a diskette from HD to DD

Format144 – the /u switch

Several people wrote to me saying that standard Windows Format supports switch /U that does the same thing as Format144, and I would like to clarify the issue.
Continue reading Format144 – the /u switch

Second Beta of Format144 1.2

I would like to thank all of you who kindly agreed to test the beta version and responded with great feedback. Here is the second beta with a couple of bugs fixed and the size of the executable file cut in half –
all I needed to do is remove symbols from the file with the strip utility. Thanks for the nice tip, Harry!

Format144 1.2 Beta

A new beta version of Format144 is available for download. It is now possible to select either drive A: or B: to use, and format 1.2MB or 720KB media, both 3-1/2in or 5-1/4in. I will appreciate your help testing it, so please check it out and let me know how it works for you.

I have to say that this version turned out to be a major challenge, and it looks like I will have to explore lower-level Windows interfaces for the future version, to make it more robust and user-friendly.

Updated Format144

There is a new version of Format144 available for download that has a couple of improvements. First, the executable is now only about a third of the size of the previous version (only 20KB!). Second, there is a bug fix – proper generation of Volume Serial Number. And now it can be compiled with GCC, which is the reason why executable is smaller! I also updated the project page to include compilation instructions and other related information.

Compiling Format144 with GCC

I received a note from one of the users saying that he was able to compile Format144 with GCC, and I wanted to try it by the time I update this project page to give you an extra compile option. After some tinkering I got it working and was so impressed by the results that I decided to switch from my favorite Borland C++ compiler to GCC for this and all my future projects. The binary compiled with GCC is only a third of the size of the version compiled with Borland, due to the fact that Borland statically links its own runtime and console libraries, whereas GCC uses standard msvcrt.dll coming with Windows. Neat, I like that.

Version 1.11 of Format144

A new version 1.11 is available, with a few cosmetic changes and an important bug fix: Volume Serial Number generation.

720KB version of Format144

I’ve created a 720K version of the utility, which was not difficult – see the left pane for download links. I plan to merge it with the original within the next few days so I don’t have to maintain two nearly identical sources. E-mail me so I can let you know when it’s ready.


I wrote a simple utility that performs unconditional formatting of floppy disks. It supplements the format functionality in Windows XP that has an apparent design flaw or a bug. GPL source code available. No installation required – the executable file is ready to run!