Floppy drives do that. I don't know about a 100% slowdown, but moving very slowly will occur. Floppy drives are not to be used as a mainstream storage media, as the I/O usage of the floppy drive, I think, slows the computer down. I think it is kind of stupid that manufacturers have not found a way to improve this over the years, especially since the only other thing to boot off of is ZIP drives, but now are becoming rare themselves. So in other words, nothing is wrong with your computer.
I will back that statment up also.
there is nothing wrong with your PC.
unfortunately that's just the way it is.