I'm presuming with a PC this old you're using IDE drives, not SATA drives, right?
What you are going to need is a PCI controller card (not PCI-e) that has connectors for IDE drives. It also has to be bootable.
One I used years ago that worked great was the UltraATA 133 PCI card made by siig. They also made an UltraATA 100 card.
IF you can find one of those, it's worth trying. They came with diskettes which you then used to insert the driver into the boot loader for Windows so it would see the controller card when you booted.
This is a link to the product from MicroCenter so you can see what it looks like: http://www.microcenter.com/product/248303/ultraata_133_pci_high-speed_dual_channel_ide_bus_master_host_controller
Good Luck
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