When it appeared that the reason that I couldn't get past the BIOS's detection screen, a few days ago, I disabled the floppy in the BIOS, and was able to boot normally. However, since I needed to be able to read a floppy, I reenabled it, and it didn't cause a problem in boot, but now neither Disk Management, Windows Explorer and the file manager that I normally use don't display the floppy among the drives.
At first, I thought that the floppy was dead, but when I selected Computer from the Start Menu, it was there as it should be, and I was able to read the floppy. Since it does work, how do I make it reappear? Rescanning the disks didn't help.