I have a dell demension 8200 computer. The cooling fan for the CPU died. When I got the new fan I went to install it and found that the guy I work with had already removed it from the computer. This fan slides into a duct that attaches to the back of the computer. Should the fan get air into the computer or blow air out the back?

My second question is when the fan failed I received an the following message when I start up:

Alert! Previous fan failure.
strike the F1 key to continue. F2 to run the startup utility.

I have gone into the startup utility and cleared the system event log several times but still get the message every time I start my computer. Any ideas how to get rid of this message?