Sometimes I really dislike computers.
A nice shiny new PC arrived containing a PIII/650 and 256Mb RAM. Unfortunately the BIOS was convinced that it actually only had 128Mb RAM, even though the big 256 DIMM was definitely in there. So after much fiddling we decided to install a BIOS update.
Naturally BIOS updates require DOS boot disks. *sigh* Much hunting around trying to find a DOS or Win9x machine later, we remembered about FreeDOS. The machine booted into the DOS variant and the reflashing utility started up. The util plastered dire warnings about catastrophic failure should the machine be powered off during the update all over the screen, so we pressed <ENTER> and crossed our fingers. During the 60s that felt more like 60years, I noticed that the utility was alternately loading data from the disk and flashing the chip. You'd think it would load all the data in first, and then flash it as quickly as possible to minimise the chance of disaster. But never mind.
Flashing complete, the machine was reset. And naturally it failed to boot at all. Oh well.