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Okay so i have a Dell demotion E521 its a AMD Athlon sires and for what ever reason i replaced windows with linux the vertion of linux i used is zorin os and can not boot this pc from cd rom or floppy disk or flashdrive i can only boot from hardrives and when i did figuer out a way to install zorin os it worked. but now i the *** computer doesnt detect and operating system even tho there is a os installed on the hardrive. so i tried this i pluged the flashdrive that has a live vertion of zorin os installed and how i boot in the os is i press f12 several times to get to the boot menu but wait theres another problem it says i have to press f1 to contiue then i do i selcet boot from hardisk and i select the hardrtive and it boots is there some way i can boot the os without the flashdrive?