Problem with the fan

A few months ago, when I got my 2 gigs of RAM, i noticed that my laptop's fan wasn't working. When I took it out, I saw that it was loaded to the gills with dust. So i borrowed my dad's airspray can to clean it out, then put it back in. Still didn't work.
Fast forward to today, where I just downloaded "SpeedFan" (freeware), and found out that according to my computer, the fan doesn't exist, even after getting rid of all that dust!
can anyone help?
Fast forward to today, where I just downloaded "SpeedFan" (freeware), and found out that according to my computer, the fan doesn't exist, even after getting rid of all that dust!

can anyone help?