I just brought this graphic card: evga Geforce 9600 gso pci express 2.0 but my motherboard only supports pci express 1.0. I did my research and pci-e 2.0 cards are backward compatible. But this graphic card has something at the end of the pins that doesn't fit into my mb. It is one of those plastic that used to lock into the mb slot but it doesnt fit on my mb. Should I cut that part? That part won't affect my gpu.
Both the card and the motherboard appear to be standard. The only thing I can think of is that you have the plastic piece that locks the card onto the board in the already locked position so just try to move it.
You need to lift up the locking clip at the end of the PCIe x16 slot before attempting to insert the graphics card. The L shaped hook part of the graphics card should fit into the hole of the lifted up clip. Once the graphics card is fully seated make sure the clip is pushed back down to lock the graphics card in the PCIe x16 slot.