Re: Windows 98
That's really strange. Windows 98 shouldn't support a SATA disk at all.
Of course, nobody on this forum nor anybody at Dell can look at your system to see what's on its disc(s) and (try to) understand why it does what it does. And nobody but you knows how you transferred the contents of the old ATA drive to the new SATA drive.
So I'm afraid you're on your own.
Luckily, it seems you still have your ATA disk. Why not keep that as a bootable disk while using your brand new SATA disk for storage only?
If I were you I'd boot from a GPARTED disk to have a look at the situation.