Hi Alex,
To be clear, are you saying you downloaded the files, but once downloaded you couldn't find them again? Try downloading something else from the internet and see where the default folder is when it appears on the screen. You can also try searching on your computer for " AC13-TG* " which should find any files beginning with that name.
Also note that they will need to be installed before they appear in the Graphisoft folder.
Hope that helps.