Vista - Cant Install Sony Vegas pro 9.0b

Ok So today i Downloaded the trial version of vegas pro 9.0b installed fine and everything but when it came to running the application that was the problem. I get this error message when vegas reaches to loading the audio engine on the splash screen and then i get this message "The Twain Manager could not be initialized. TWAIN_32.dll missing or corrupt" what could be the problem here i know this file is to do with scanners and cameras however i have none of those connected to my laptop im lost if anyone has any thing please. oh just for the record i have check that wow.exe thing that some other people have suggested and that solution does not work i need help i wanna use Vegas to make music videos and stuff.