well, im trying to install win98 in an old computer but it appears that i need to create a partition. I use fdisk to create it but appears the message NO FIXED DISKS PRESENT. What can I do???

Watch the screens during the startup. The harddrive should be identified by model number. If that doesn't happen then boot into the BIOS screens (setup) and verify the harddrive is showing up there.

Also when in the BIOS screens check the date and time. If the date is wrong then the CMOS battery is weak or dead. The boot order may be set wrong.

Depending on which version of Win98 you have you probably need to use a Win98 boot floppy.

Verify there actually is a hard drive and that it's properly connected. Go into cmos/bios setup and make sure both IDE controllers are enabled and the drive is correctly identified--usually as AUTO.