XigmaNAS

I have an old computer; it won't boot from the NAS4Free-x86-LiveUSB-9.2.0.1.943.img file. I wrote it to a USB stick using Win32DiskImager-0.9.5-install.exe. It attempts to load, but resets itself and restarts the boot process.
The computer will boot from a Ubuntu live USB stick. It has a 32-bit AMD Sempron processor and 1GB of ram. I also tried a brand new USB stick- same result. It will also boot from NAS4Free-x86-LiveCD-9.2.0.1.943.iso written to a CD. I checked the NAS4Free-x86-LiveUSB-9.2.0.1.943.img to see if it was secretly a .gz file that needed extracting, but it isn't.

I could give up and use the working CD I made, but I'm still curious: what could I be doing wrong?

Try to install the embedded Version with the cd you have to an USB Stick

You might be writing the img file directly to USB without extracting it first.

You can follow the guide here :-
viewtopic.php?f=55&t=2106

That is indeed what I'm doing RedAntz because it's the -LiveUSB- version that I'm writing. The instructions say "You can skip step 3 if you use NAS4Free-x64-LiveUSB-<version>.img". Also as I said, I tried renaming it .gz and extracting it, but it wasn't a valid gzip file.

I checked the MD5 of the file, just in case, and it comes to 5215d9ba20a3012f2eea0258e013e0c5 which appears to be correct.

Try physdiskwrite --> http://wiki.nas4free.org/doku.php?id=fa ... sdiskwrite
In the past I encountered such problems with win32diskimager while using physdikwrite with the same USB stick+IMG had no issues...

Thank you for the suggestion, although it looked promising because it was different (previously diskmgmnt.msc reported 24MB 'healthy' the rest unformatted, now the whole drive is 'healthy' although browsing to it triggers an "unformatted" msgbox) however, it too failed. I will try Apollo567's suggestion of installing it to the USB stick. If anyone could suggest how the stick should be prepared for this, that would be great, otherwise I'll just try it formatted FAT.

[IMHO] USB booting just sucks, especially on on older equipment.
OEM supplied bios were [again IMHO] not robust in this area.
I avoid it all together using industrial grade IDE PATA or SATA flash
or small [95 era] Hdd set to spin down after the embedded load to RAM.
USB booting is great when it works, PITA when it does not.

some encountered problems
complex USB memory sticks with self loading drivers and non fat file systems.
bios booting 16 bit file limitations [I think} or some aversion to sticks 2 Gb & up
not all USB ports boot and unclear bios choices

most reliable is booting in the same way the hardware was delivered
here too; some times only the primary IDE line will boot.

$18. and never a problem http://www.logicsupply.com/components/s ... h-modules/
no problems with salvaged 2 or 3 Gb Hdd one built with one of these 1.7 Gb is still working
http://www.ebay.com/itm/FUJITSU-M1623TA ... 483b49d943
one can usually find an old Hdd in the junk box. or ebay cheaper than the above

more reliable than USB [again IMHO] is live CD and a USB stick for configuration file storage
slow to boot, but once the OS is in RAM, it is as fast as it will be on any given hardware

Interesting opinion Armand - I hear you on this. And yet, Ubuntu on a flash drive seems to work ok, at least as far as booting up (saving state and casper etc. is another story, but I digress).

another issue/solution in getting usb to work for booting N4F

once the usb stick has a real MS FAT file system,
I always have loaded from the live CD. usually on the target equipment,
often with a known good CD/DVD drive hanging out the side.
while this loading is a bit risky if done on ones desktop. [one can accidentally wipes the C:\ drive. ]
[if one is not confident one can unplug the C:\ drive to avoid a total sebelious]
it has two distinct advantages [again IMHO] one avoids other OS and disk write programs
and by booting the N4F live CD on the target hardware, I know it is less likely a hardware problem.

I tried formatting the USB with FAT, booting from CD on the target and asking to install to USB. Same result; 24MB partition 'healthy', the target hardware goes into a reboot loop. I'm done trying, I'm going to boot from live CD, thanks for the help!

the small fat partition is likely due to space set aside for a self loading driver
the rest of the space is likely in an unrecognized storage partition
first delete all partitions on the USB drive