Not any more. Here is a step by step guide on how to get that elusive book onto the kindle. With pictures :)
This bit goes into your kindle as if you were charging it.
remove the other end from the plug like so. At this point a kindle fire needs to be turned ON. My paperwhite or keyboard kindle doesn't need this.
and put into the USB port on your computer
This window pops up. Click on the first option.
Now unless your using a kindle fire, this window opens. A kindle fire opens another window first, that says internal storage. Click on that to open it and you get this window
Click the document folder to open it
it gives you all your books you already have on it.
Now at the bottom of my comp screen are the books i want on the kindle.
just put your mouse over it and drag and drop into the open document window as many times as you need. Wait until each one has finished loading first though.
Remove the kindle properly, don't just yank the cable out.
and then remove the cable.
And there you go. All ready to read your new book.