help me out..

actually that depends could u tell me ur computer spec?
ram
GPU
PROCESSOR.
and motherboard

Wow. 25fps in a 4 year old game. Your computer must be complete crap, lol.

Lol ,just because he may not have an intel core 2 quad ,or sandy that doesnt really give you the right to tell if his/her computer is crap .
An this 4 year old game is laging on my intel core 2 quad 9550 and ati hd 4870 toxic (yes ,i know ,its old but i can to play crysis 2 almost maxed at 1600/1200 and i can to play this game even at medium on this resolution ,cause of the bad coding that this game has)
Well in regard of your problem with the low fps ,you must "downgrade" your setings espeacialy your resolution to something like 1024/768 or 800/600 or 801/601 whatever fits you the most .The game bosster thing doesnt rlly work ,just stops some shty programs that you have runing on desktop ,i can guarantee you that gameboster ,in the best case will give you like 2 fps + or maiby a litle bit smoother gameplay ,but will remain still chopy and unplayable .You know the thing with "+" or "-" on ava? You can downgrade your image quality for you to gain some fps ,for some guys works a litle to much (gaining maiby like 20 -30) and for some just 1 -10 fps ,you must try.
Mate you must search on the forums for "Tweaks" for ava.If im not mistake you will find here the ava.ini file with the tweaked comands.
If you put that file ,you downgrad resolution ,use the "-" i can asure you that you will gain like 20 fps and a smother gameplay .You should try gameboster too ,but like i said (i admire the producers of this program dont understand me wrong) it's not gonna make an infinite diference.
Sorry if i misspeled ,im drunk .[COLOR="Silver"]