I will try to be more specific :
I can boot from a floppy like win 98 SE etc.........
If I have some files in the floppy, I can copy one file to the same floppy
If the floppy is not empty, I can send a file to this floppy !
But if they are no directory in the floppy, my computer freeze and I have to hit the reset.
I have not trying in safe mode but this is the next step
Yes,
That is working in safe mode,
No problem, I can read, write and format
Maybe this is a software who is locking the floppy