Recommendations for this kind of Windows "001" File Joiner?

I’ve tried more than a dozen file joiners, but not one of them works as follows:

(1): Automatically launches when any file with extension *.001 is double-clicked.

(2): Does not bring up a GUI which requires even minimal user interaction.

(3): Does not ask me if I want to keep or delete the source files (I always want to keep them).

(4): Does not present any dialog box of any kind at any time.

I’ve used the paid MasterSplitter app for some time, but it violates (2) and (4) in that every single time it requires user interaction to press some GUI button to begin the joining, and then when it finished, it popped up yet another dialog box “informing” me that the file extension might not be appropriate for DOS usage! So that’s out.

I’ve used the freeware Cheshire Cat’s One-Click file joiner, but that violates (3). And besides, I’ve had no end of trouble forcing XP Pro to launch it when double-clicked. Windows simply will not let me either change the file association to it in a *.001 file properties window or add it permanently to the “Open With…” list! It will run only after bringing up an “Open With” list that requires manual navigation to the Cheshire executable file, and I have to so navigate each and every time I want to join a *.001 file!

I bought Boilsoft’s latest commercial media file joiner, but that violates (2), such that it launches a full GUI app that requires user interaction. What a waste of money!

I tried several other freeware joiners, one of which (Katie’s?) contained viruses/trojans even though they were openly listed as freeware (not warez!) and came from seemingly reliable sources. Others failed with obscure error messages about missing files. And the rest violated (2). (3), or (4) anyway!

SO: Does anyone know of a Windows minimal *.001 file auto-launching joiner that does not use a GUI and simply joins the files with no user intervention required whatsoever?

is it possible to write a batch file that uses copy /b and associate it with .001 files?

Not really, because the list of files will be different every single time. I’d have to write a program to generate a unique batch file containing a copy command for the unique list of files/filenames, then launch it. But it would make more sense for me to write my own file joiner than to take that route, and although I could certainly develop a joiner program myself, I’d rather spend my time on other activities and use someone else’s program.

HJ Join

Where do these .001 files come from?

you can associate *.001 files with a batch file (stored anywhere in the PATH) which simply does something like this:

copy /b %~n1. %~n1.joined* (replace “joined” with your desired extension and remove /b if you’re working with ascii)

They come from (among other places) HJsplit, which is a file splitter. See the HJjoin link above.

File splitters allow disk spanning and CD spanning. They also permit the posting of very large files over usenet, some of which are public domain.

The .001 files I’ve seen come from Scandisk finding orphaned files on a hard drive that don’t have a name/directory entry.

Don’t people just use RARs for the exact same purpose, with added benefits of compression and even Reed-Sollomon error detection and recovery? WinRAR also lets you right click and choose “extract into this folder” without GUI, etc. (and can probably be configured with a flag to do the same on double-click).

I’ve seen orphaned files be named .001 too. But in that case, I don’t imagine splicing them together would do anything.

As others have noted, .001 files are used for a variety of tasks, not just file splitting. This is why utilities tend not to associate with the extension - because the split file is not wrapped or marked in any way, a file splitting utility cannot figure out in any way whether the .001 file is a part of a split file set or not.

As Alex pointed out, in places that rely on file splitting (generally Usenet, due to a 15Mb posting limit), people use both rar (to create a suitably tagged container format for the split files) and par2 (error detection/recovery) to allow reliable file splitting and data recovery if segments get corrupted or lost. The latest version of rar (rar3) can create recovery volume sets as well as compressing/splitting, but is a proprietary product that must be licensed.


Thanks to all. By using the Wayback Machine to search for an old URL, I found precisely what I wanted. It’s nothing more than a dll (Joiner.dll) that requires no installation and instead shows up in the right-click context menu after nothing more than copying it to the System32 directory and registering it. No command lines, no GUI, no struggling to associate it with .001 files, no hassles at all.

Unlike HJ Join (and many other similar tools), which the HJ Join web page implies is only compatible with files that were split with HJ Split in the first place, this critter is independent and universal.

HJ Join works with everything as well.