I have a Packard bell iStart 2389 running Windows Vista Home Premium with a Seagate Tonka II / Barracuda HDD, I would like to also install Windows XP Home Edition, I have a new XP disk and I have partitioned my hard drive but when I try to install XP the option to install is there but I am unable to choose this, I do not know a lot about computers and have no idea what I need to do, some research has suggested this is something to do with the sata drive but I have no idea what to do next,any help would be appreciated