[dogscoff]

Either your download is duff- in which case redownload, trying both sites as suggested already - or your se4.exe is somehow knackered, in which case you'll have to re-copy the file from your se4 CD.

I can't remember offhand whether you can copy this one file without re-installing the whole game or not, but if it does come to that, re-installing shouldn't lose you any data just as long as all your mods are safely tucked away in their own sub-folders.

Oh, it could also be that you're trying to install the 1.84 patch onto se4 classic (ie not se4 Gold). Check which Version you have. If you have a non-Gold cd then the best patch you can have is up to Version 1.49