You need the bigfat.exe...use it. Some antivirus systems says that the file is a virus, but it's not. Download it. Than copy the bigfat.exe file to the fifa08 main directory. Start game with the bigfat.exe. Play.
For the patches...Most of the patches are cmp files. Use Creation Master 08. Before you start to load a patch for your Fifa, you need to delete the Fifa directory in your Documents and Settings directory. Load the cmp file in CM08/patch menu. Start it. After install, save and exit. Then start the game with the fifa08 bigfat.exe