HELP PLEASE!! HELP PLEASE!!

Can any one plz help me i just installing mw2 and the alteriw net thing..... it opened up and stuff but when i open iw4mp.exe ... i select start old iw4m1 the when i press that i get this error "" System****.FileNotFoundException: Could Not find file 'zone\english\patch_mp.ff' at System****._Error.WinIOError.WinIOError(Int32 errorCode, StringmaybeFullPath) at System****. Fileinfo.get_length() at VerifyMW2()"" i looked in that directory 'zone\english\patch_mp.ff' patch_mp.ff file was not there i looked all over the internet to find that file and could not find it does any one kw how can i fix this problem or upload patch_mp.ff for me?

redownloading it is the best solution