How can i fix this computer problem?

my computer been messin up... it keeps on popping this window every time...it says i need 2 finish installing the program, but i've try n it doesnt work cus i dont hav some file that would save it... want i wanna do is jux take that off cus i'm not able of downloading anything else because of that... how can i stop it from popping up??? HELP!!! IS URGENT!!!