After many downloads and unistalls and reg cleaning - I finally got passed the "CRC mismatch" error - only to run into this new error on install - "The cabinet file 'main.cab' required for the installation is corrupt and cannot be used." "Click ignor and i get " Internal Error 2350"

This is from the download on the sony site -

I have purchased and am dying to get to use my Vegas but it just WILL NOT INSTALL????? HELP SONY OR ANY ONE LISTENING