Very low internet speeds on a single Windows machine
Very low internet speeds on a single Windows machine
The Issue: According to the details above, I’m experiencing only 0.18 Mbps upload speeds. Downloads are okay. This occurs exclusively on my main desktop computer. Laptops and mobile devices work without issues. My ISP plan offers 200Mbps down and 30Mbps up, while other devices maintain regular performance. The issue appears with both Ethernet adapter and the built-in Wi-Fi card. I noticed it today, but I suspect no recent updates were applied. When connecting directly via Ethernet from the desktop to the ISP modem, speeds return to normal. This suggests the problem lies between this PC (with wired and wireless adapters) and the Netgear router. All other computers and mobile devices remain unaffected through the router on wired or Wi-Fi connections.
Hardware: PC – Mini ITX (built myself a few years back). No other concerns. AMD Ryzen 9 3900X, Gigabyte X570 Aorus Pro Wi-Fi motherboard, MSI RTX 2080 Ti GPU, 32GB RAM. Windows runs on a 2TB Samsung 980 Pro NVMe SSD. Secondary drive: 2TB Samsung 970 Evo Plus NVMe SSD. Third drive: 2TB Samsung 850 Pro 2.5" SATA SSD. Router: Netgear Nighthawk R6700v3. Today I updated the firmware to version V1.0.4.128_10.0.104.
Troubleshooting Attempts:
- Restarted router and modem; factory reset Netgear device. Updated firmware no change.
- Checked for Windows updates – none recent or needed.
- Reinstalled drivers for Nvidia; speeds still unchanged.
- Deleted and reinstalled network adapters after restart; no improvement.
- Executed gpedit.msc via text file; found it, enabled it, set bandwidth limit to 80%. Still no boost.
- Switched Ethernet cable; speeds remained normal.
- Disabled IP Helper and Windows Management tools; no effect.
- Adjusted QoS settings in Group Policy; temporary uplift to 2Mbps, then back to 0.35Mbps.
- Ran network troubleshooter; no issues detected.
- Tested WLAN and WWAN auto-configuration; both set to automatic.
- Rebooted PC after changing cables and settings.
What I’m Experiencing: All other devices connect smoothly through the router on any connection method, but this specific machine consistently underperforms. The speed drop only appears when using Ethernet directly to the modem. No signs of malware or VPN interference beyond Windows Defender.
Recommendations:
- Consider checking physical connections and cable quality.
- Verify that the ISP service is functioning correctly and not throttling.
- If possible, try connecting via mobile hotspot to rule out local network issues.
- Explore alternative network configurations or contact Netgear support for further diagnostics.
- If the problem persists after these steps, a hardware inspection of the PC’s network interface might be necessary.
Have you verified your antenna connections? Have you attempted a wired setup? Did you perform a clean Windows installation?
Have you verified your antennas for a solid connection? - All are linked. Have you attempted a wired setup? - Yes, the issue continues on both wired and wireless links to the router, but disappears when using a direct wired link to the modem. Have you considered a fresh Windows installation? - No, not yet, but I’m hesitant about it.
Place it on an affordable storage device and start up from there.