Friends have an old Pentium III (if necessary, I'll sign the hardware for more). There were problems with loading and I set it in BIOS: Load optimized defaults . Default settings. It began to load normally. (More precisely, first of all I put "Load Fail-Safe Defaults", and then "Optimized ...", but this probably does not matter.)
There used to be the first boot device - CD ROM, it became Floppy. The second device is HDD. I put again First boot device: CD ROM But no! It is loaded only from the hard drive!
Question: what does he, the dog, still need? :-)
PS No physical connections have changed. Before that (i.e. resetting the settings to "default"), the first one was booting from a CD-ROM.