To view BF2 demos you need to follow these instructions 
- My documents/battlefield 2/profiles/default/
- Then create a directory(folder) named "demos" inside the default directory.
- Place your downloaded demos into this folder.
- Open up Battlefield 2.exe & log in
- Open the community tab (in-game)
- The demo should be viewable and then you should be able to play it.
Demo names are as follows: "auto_2010_06_23_02_34_40.bf2demo"
broken down it means: auto record_year_month_day_hour_minuet_seconds(demo started to record ).file typeIt is the same exact process for BF2142 just in that game instead !.