Step 9. If there’s limited room inside the case, you might have to pre-attach the power connectors to the new card.
Step 10. Install the new graphics card, first making sure that no small wires are overhanging the PCI Express slot. If the card seems difficult to push down, check to see whether the connector bracket is sliding in properly.
Install the new graphics card in the correct slot. Here, the turquoise slot is too small
Step 11. Once the graphics card is firmly in place in your PC, replace the connector-bracket screws.
Step 12. Attach the monitor cable. If you’ve previously been using a VGA cable and your monitor has a digital input (DVI, HDMI or DisplayPort), now is a good opportunity to switch to using a digital input with the right cable.
Step 13. Double-check to confirm that the graphics card’s power connectors are in place. Additionally, verify that no small wires or cables will interfere with any of the cooling fans.
Organising cables makes it easier to access the PC's insides later
Step 14. Power up the PC. If you hear any rattling, it indicates that something is rubbing against the fans; power down and check to make sure that no fans have become blocked.
Step 15. Once the system is powered up and running normally, install the latest drivers for the graphics card. Following a final reboot, your card is ready for use.