Your PC is running, but the dedicated GPU is missing from Device Manager or Task Manager, or the monitor says No Signal when connected to the graphics card ports. This guide applies to desktop computers with a separate add-in graphics card, including new installations and cards that suddenly stopped appearing.
Does This Affect You?
A “not detected” graphics card usually shows up in one of two ways: Windows only lists integrated graphics, or the monitor gets no signal from the GPU even though the system powers on. Both symptoms usually lead back to display routing, PCIe seating, missing power, or a driver conflict.
Check the Monitor Cable and BIOS First
Before opening the case, make sure the display is connected to the right output and the firmware is not forcing onboard graphics.
- Plug the monitor cable into the graphics card, not the motherboard video ports. On most towers, the graphics card ports sit lower on the rear of the case in the expansion-slot area.
- Restart and enter BIOS/UEFI setup, usually with Delete, F2, F10, or F12 during startup.
- Look for a setting named Primary Display, Initial Display Output, Init Display First, or similar. Choose PCIe, PEG, or the graphics-card slot instead of integrated or onboard graphics.
- If BIOS appears normally through the graphics card output, the hardware is at least producing video. Move on to a clean Windows driver check.
- If BIOS also shows nothing through the card, continue with the physical installation steps.
The next steps involve opening the computer. Shut it down fully, unplug it from the wall, and touch bare metal on the case before handling internal parts. Handle the card by its edges and metal bracket, and avoid touching the gold PCIe connector or components on the board. These steps are at your own risk; if the system is under warranty or you are unsure, contact support.
Check the Physical Installation and Power
A graphics card that is slightly lifted out of the slot, sagging, or missing a power lead may not be detected at all.
- Open the case after disconnecting power.
- Confirm the card is fully seated in the PCIe slot. Press gently and evenly along the top edge until the slot latch is engaged.
- Check every required PCIe power plug from the power supply. Depending on the card, this may be one or more 6-pin, 8-pin, 12VHPWR, or vendor-specific power connectors.
- Make sure the bracket screw at the back of the case is installed so the card sits level. A card that hangs at an angle can lose contact over time.
- If the motherboard has another full-length PCIe slot, try the card there to rule out a damaged slot.
- Reassemble enough to test safely, power on, and check whether BIOS or Windows now sees the card.
If the GPU appears in Device Manager but is disabled, right-click it and choose Enable device. If it appears with a warning icon or the system recently had another GPU installed, use Display Driver Uninstaller in Safe Mode to remove old NVIDIA or AMD drivers, then install the latest driver directly from the card maker or GPU vendor.
A card that is detected briefly and disappears under load may be exposing a power problem. Compare the GPU manufacturer recommended power-supply wattage with the actual PSU in the computer, including the required connector type and cable arrangement.
If the card is seated correctly, has enough power, fails in more than one PCIe slot, and still does not appear after a clean driver installation, test it in another computer if possible. A known-working card in your PC, or your card in another PC, is the clearest way to separate a failed GPU from a motherboard or power-supply issue.
Sources
- NVIDIA Support – Graphics card not detected troubleshooting (2025)
- AMD Support – GPU not detected in Windows or BIOS (2025)
- Microsoft Support – Fix graphics card detection issues (2025)