OK, easy enough. download the gadget again. Rename to:
You'll get the warning that changing extensions blah, blah, blah...just click ok, now you'll have a zip file.
Extract the files to a folder on your desktop named:
Drop that folder into C:\Users\(Your Name)\AppData\Local\Microsoft\Windows Sidebar\Gadgets folder
Check your gadgets and it should be there. If not, here's something you might like too: Chameleon Glass by ~gersma on deviantART
Let us know how it went, good luck. A Guy