Borrow someone's 98 boot floppy diskette (or download a file that will make one for you). If you're making your own, format it first to make sure it has no bad spots. If it does, chuck it and find another floppy that's clean.
Insert into your floppy drive, go up into the BIOS to make sure boot order has the floppy second after the cd drive. Also, if RAID is enabled, disable it. If you have an option for IDE mode, choose that.
When you get an "A" prompt, type fdisk - say no - then do a display partition to see what's there.
By ALL MEANS, upgrade your BIOS. These things are very safe and take only about a minute to do. Again, if you're doing it with a floppy, format it first to make sure it's clean. Then load the BIOS stuff onto it.
However, brand new off the shelf? Has to be a jumper issue. Check the literature that came with the drive. Make sure the SATA jumper is 150, and if there is a clj jumper, remove it. If you have black connectors, use that. Then fdisk and delete all the partitions and start over.