I'm not sure what your situation is, exactly. IconPackager doesn't remove the taskbar. It changes the Windows system icons, such as those on your start menu and folders, picture files, and so on that you see when you browse through your folders. I can't tell what you did, but the way to apply an IconPackager theme is to open the program, choose a package that you see in the list at the bottom, and click "Apply Icon Package" on the left. When you first open the program, there may not be any in the list. If not, go to the Wincustomize galleries, find the IconPackager gallery, and download some. If it is not a .zip file, you can either double-click on it to get it in the list, or add it using the "Add Icon Package" button on the left in IconPackager. When you click on "Apply Icon Package", the program will replace the Windows icons with those in the Icon Package. On a slow computer, this takes a bit of time. Give it a chance. You don't need to restart your computer.
I'm curious as to how you uninstalled IconPackager. You should do it using Impulse, a free Stardock program that you can find here:
Once you have removed it, reinstall IconPackager, and try the above instructions. Before you do that clean the computer of temporary files, and clean the registry using a program such as CCleaner, which you can find here:
If you deleted the IconPackager folder in Program Files, there will still be bits and pieces in Local Settings, etc., that you may have to track down. I don't know what the error code 65535 indicates.
Try these things, and see where it gets you. Before you try to create an Icon Package, find some tutorials, or post a question. Good luck.