I had a case of a program that had to run with admin rights, it was storing the info in some of the first sectors of the HD (yes it's possible without direct ha

I had a case of a program that had to run with admin rights, it was storing the info in some of the first sectors of the HD (yes it's possible without direct hardware access, you "just" need admin rights). Of course it corrupted my GRUB... they didn't think that there might be useful data between the MBR and the first partition. This happened around 2010, so no need to go back to Windows 9x to find very weird stuff ;)