Ive just removed my fan to check the processor, but ive forgoton where the screws go & i cant clip that silver box back on, the bracket seems a bit short. Ive got a elite motherboard with amd duron 800mhz processor.
I do not know exactly what you are saying but if you have disconnected the fan assembly from the heatsink it is screwed normally by four screws, one in each corner. The heatsink is attached by spring clips, attach one on first the gently push the other on down using a screwdriver. Get some fresh thermal paste and make sure the old paste is all cleaned of the processor.
AMD clips can be a very tight fit, you may need to use some force. I assume when you refer to 'that silver box' you do mean the heatsink, it should look a little like this [URL=click here][IMG]. You MUST use some thermal compound in between don't try to put is back together without any or it might overheat and you must make sure to clean off all the old dry compound too. Here is a video clip on installing it properly, just scroll down to 'Installing an Athlon XP, Heatsink and RAM' click here#_ it is almost exactly like installing a Duron.
If you put the fan on top of the heatsink and drop the screws in the holes then the screws will line up in between the fins but make sure you get the fan the right way up or it won't blow air in the right direction.