I am getting ready to install Windows 7 on my XP computor. Have checked and my computor is suitable. My present computor has 2 Harddrives, each harddrive has some partitions. Will a Windows 7 update effect files on the harddrive without the operating system? Re the partitioned hardrive with the operating system will the non operating system partitions be erased or effected during the Windows 7 installation? I do intend to revise partition sizes on the harddrive with the operating sytem at some point am I better to do this now before the Windows 7 Installation?