star window 98

i bought an used computer, and i can’t open it,
because after i boot it, i saw the phrase : ”
press ctrl-alt and enter to system setup, and then the window system sepup display, and i don’t
known how to display window 98, when i reboot , and setup by start disk win98, then the setup stop
because : the computer installed win 98, so i couldn’t do anything, please help me to open it
Thank you so much .
Khanh Huynh