I have Vista Ultimate SP1, and i've downloaded sidebar gadget but windows wont read the extension file, (.gadget), did i forget to install a program or something???

yeah i did, even if i dont have the sidebar open, when i double click to try and launch the gadget it launches the sidebar instead. the extension on the file is .gagdet, so i know its right, and i see other people have downloaded the same gadget. I just dont get it, i thought it would be simple enough. Download the gadget, double click to open and viola! but nooo....

That should be how it works. I have opened many gadget files and a install dialog from Windows Sidebar appeared.
If Windows Sidebar is already open and you open a gadget file what happens?

The gadgets that are pre installed work fine, except the weather one, but so far i have no gadgets on the sidebar. When sidebar is running i double click to launch the new gadget, all it does is bring up the sidebar from the background. (you know how the sidebar fades out if your not ON the sidebar). Ive already done what madmac has suggested, its like i cant even open the file so i can see what's "inside" the gadget folder. Like i can look at the gadgets stuff from the c-drive. I think im just freakin' retarded. whs, where would i find that file association option.

i never said it was resolved, i was answering WHS question about checking the file association!!!! Its not solved, my gadgets still wont work!!!

Thanks LH!!! I tried downloading other gadgets and either dropping them to the sidebar, but it doesnt work.... im gonna try to provide images when i get off from work.

deleting what exactly? I have no gadgets but the preinstalled ones.

That is the best way to solve a problem - get another PC. LOL