OK, this one we have something to go on because you're being quite specific.

Is there a way to make a portable fridge using a radiator and other parts?

No, not really. You haven't got answer because there isn't a reasonable one.

How can i add vista theme on windows xp?

There's an Instructable on this, people are just as dis-inclined as you are to use a search function, because they think you're lazy.

Why the PDF on the site doesn't work?

You received a satisfactory answer.

L

You may have to provide more information for your questions and also remember that noone is in any way obligated to answer your questions. People volunteer their time and knowledge altruistically without any compesation.

http://www.google.com/search?q=how+to+ask+good+questions&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a

Some of these are phrased a bit roughly, but many of them have good advice on how to write a question that people will be able -- and just as importantly, want -- to answer.

People answer those questions they ...

... find interesting.

... are able to answer.

... need more than a simple google to answer.

(There you go; now exactly half of your questions have an answer.)