|I'm only going to provide you with a basic answer because I'm not the most advanced computer user. I hope it solves your problem.|
If you have moved the main location of the items you have shortcuts for you will have to delete the current icons and redefine them.
As for your gadgets you should be able to replace them by going to start - acessories - windows sidebar. I've had the bar disappear on me a few times now. I don't know the cause but it's quite irritating