Data file too short

[player22bob 0]

ok i have a start up problem and i will go through what ive done so far.

i brought arma 2 and arma 2 OA today on the steam sale, i launched arma 2 all the way to the multiplayer menu but didnt do it for arma 2 OA (mistake #1), tried to launch dayz through dayzcommander after updating to the new dayz and arma 2, but it wouldnt let me launch the game, my error is as follows;

Data file too short 'c:\program files

(x86)\steam\steamapps\common\arma 2 operation

arrowhead\@DayZ\addons\dayz.pbo'. Expected 25270671 B, got

16776192

i then tried to launch arma 2 OA straight from steam and came up with same error. i deleted both arma 2 and arma 2 AH files and reinstalled both

games, launched arma 2 straight from steam again and it worked all good then tried arma 2 OA and it came up with same error.

i then closed steam completely and reopened as administrator then clicked on arma 2 OA / properties / local files / verify intergrity of game cache... waited for that to finish and it came up

'1 files failed to validate and will be reacquired'

and the close botton nothing else, im guessing its referring to the error but it doesnt give me a solution.

after all this i took a risk and just deleted the;

dayz.pbo

from the files and it started up straight away, it worked all the way past the mission breifing and then it said

you have an outdated version of 'dayz_anim' please download the correct version

hopefully this helps me get one step closer to playing the game haha, i have put the dayz_pbo file back its original spot and i also tried to read the file but it goes on for a long time and it has alot of rubbish in it.

PS. my brother had his saved arma 2 and arma OA on my computer login from when he was using his steam account on it, not sure if that helps or not.

Thank-you for your time and hope to hear a response