As you know, on the modern operating systems such as Windows 7, Serious Sam: SE refuses to run at all, even ignoring the compatibility mode, because of the fact that the engine itself simply can not get accustomed to the new core system. I think there is no need to describe in detail the nature of the problem, it is not as interesting as the decision itself of this trouble, and it is available and it is very easy: Download the executable exe-file of the game, specifically designed to drive Win7. The only problem is that this is an unofficial fix, and therefore the network to get it quite problematic, especially so give you link to download.
Place the downloaded file in the folder bin, which is in the main game directory. Agree to replace the file, and all can start and go chop meat)
Скачанный файл поместите в папку bin, находящуюся в главной директории игры. Согласитесь на замену файла, и всё, можете стартовать и идти рубить мясо)