Lady of tdaxp is planning on replacing her notebook in the near future, so I (ever valiant) offered to backup everything on her laptop to my portable USB harddrive. I opened the dos prompt by entering “cmd” in the Start | Run dialog of Windows xcopy, typed the necessary command to xcopy and got an “insufficient memory error” when it got to copying over the file ntuser.dat Using Microsoft’s “wrapper” for xcopy…

@echo off
rem COPYIT.BAT transfers all files in all subdirectories of
rem the source drive or directory (%1) to the destination rem drive or directory (%2)

xcopy %1 %2 /s /e

if errorlevel 4 goto lowmemory
if errorlevel 2 goto abort
if errorlevel 0 goto exit

:lowmemory
echo Insufficient memory to copy files or
echo invalid drive or command-line syntax.
goto exit

:abort
echo You pressed CTRL+C to end the copy operation.
goto exit

..merely confirmed that I had run into a fatal low memory error. DOS bat files, unlike other basic programming languages, does not have an “on error resume next” command, so I could never get more than a small fraction of the drive copied.

(I didn’t even try with the simple Copy-and-Paste feature of Windows, for the same reason that I don’t try jumping-out-of-the-windowas a convient way of moving from my fifth floor office to the ground below when I leave work.)

Fortunately, I found a free program called xxcopy which is in every way an improvement over the xcopy included in Microsoft Windows. XXCopy accepts the same command line arguments, but also includes some new ones which make things easier to remember. So now I can enter “xxcopy c: f:backup /copy”, and the drive is backed up.

And the ntuser.dat error? It turns out Microsoft lies (no surprise). Mere users don’t have permission to make back-ups of their ntuser.dat profile pages, but to hide this fact from the naive the command box makes it look like you need to go out and buy more memory. XXCopy isn’t able to force a copy, but it is able to go around the problem — giving up on files on your comptuer that you own but Microsoft won’t let you backup, and continuing to copy the rest.

So: xxcopy. Good software. Good price (free). Good deal.