The short answer is no. However, there are some limits on downloading skins from WinCustomize depending on whether you are a subscriber or not & whether you own Object Desktop or not.
If you're using IE, the way it handles the download can be dodgy on some rigs as IE has a tendency to rename compressed files I understand (the skin files are standard .zip files with a .wba extension so that WB is the handler rather than WinZip). Try right-clicking the Download button, select "Save Target As..." and save the .wba file on your hard drive somewhere. You can then either double-click the .wba file to install it or open WB Config, select "Install Skin from Disk" and navigate to the .wba file and select Open. The benefit to doing it this way is that you have the .wba source file & you can re-install the skin if you ever need to without having to go to the net for it.
If the skin still doesn't show up in the installed skin list after either of those maneuvers, there may be something about the skin file that is wrong - maybe it's a .wba file inside a .zip or some other problem.