Windows 8.1 Missing program files

Hello, A week ago i upgraded my windows from 7 to 8.1 straight away. Now i noticed when i tried to get some old files back from my windows.old folder, there isn't anything in there! I know that windows 8.1 has an build in timer which will automaticly remove this folder after 28 days, but thats not the case. All files from my last OS are still at my harddrive, because it tells me the same...