Troubles getting debian to run

["Les C." <lester061755@gmail.com>]

I downloaded the 3 dvd .iso files for the i386. Trying to bootup on a 32gig usb stick, started by extracting the iso files to the stick and rebooted, changing the bio to boot from the stick.  Could not get it to work.  Then after reading the website, i noticed a section that stated that you could just just copy the iso file to the stick so formatted the stick and copied the 3 iso files to the stick and tried again.  Got "BOOTMGR not found" error.  Thanks for any help.