I think Don has it. I am running 5 Windows PC's. FF is my default on 4 and SM on 1. The best and easiest way for me to transfer bookmarks is to export to the desktop, and then copy that file across my network.
Then if I want to update IE, I import form the desktop file.
But, IE has a different file structure than does any Gecko browser. You can go into WinExplorer and find a Favorites folder, and each favorite will be a file in the folder. You cannot do much with that. But, you can import it into FF, SM, etc., and then make the desktop file.
Depending on how Safari works, and I have had it a couple of times, I think that you can import the file from the desktop. I think that is what I remember doing.
I have used IE only a wee bit more than Safari, so my Favorites files are very out of date. I hope that I am remembering this correctly.
It should not be hard or take very long.
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:184.108.40.206) Gecko/20101203 Firefox/3.6.13 ImageShackToolbar/5.2.4 ( .NET CLR 3.5.30729; .NET4.0C)