here is a screen from disk management. IF i wont lose the stuff i put at DİSK 1 (backup of my files) when i install 64bit to the DİSK 0 , then i dont have to delete or format Disk 1 . I am just scared that i wont be able to acces DİSK 1 because it contains and old 32bit windows 7 folder. If someone can assure me that i'll be able to access Disk 1 files without a problem i'll install 64 bit today.
installing a new OS in a different hard disk or partition will not prevent you from accessing the files from the other disk or partition. just take care not to delete or format the partition you wish to save during the installation of the new 64 bit windows. as always, make a backup before you do anything.