I presume that you are actually trying to fit this card into a PCI slot (these are white) and not an
ISA slot (coloured black) or the maybe unused AGP slot (coloured brown). It will only fit into the white PCI slot one way. Check that no obstruction is in the way - bent pins in the slot for instance. Also that there is no damage to the card itself. Just line it up correctly and apply even pressure along the full length of the tp and push down on it. Should be a fairly tight fit but it should go down into the V slotted pins correctly.