How to Fix Slow WiFi Upload Speed on Windows PC: Drivers, Settings, and Hardware Fixes

Slow upload speed on a Windows PC is one of the most frustrating WiFi problems because it’s so lopsided — your downloads are fine, your phone gets full speed, but your PC struggles to push anything out. The good news is this is almost always a software or driver issue, not a hardware failure. Here’s how to fix it, starting with the solutions that work most often.

Step 1: Confirm It’s Your PC, Not Your Connection

Before touching any settings, run a speed test on our homepage from your PC and then again from your phone on the same WiFi network. If your phone gets 50 Mbps upload and your PC gets 2 Mbps, the problem is definitely on the PC side. If both devices are slow, the issue is with your router or ISP and you should read our guide on fixing slow upload speed across your network instead.

Step 2: Update Your WiFi Adapter Driver

An outdated or corrupted WiFi driver is the single most common cause of upload-only slowdowns on Windows. Microsoft’s generic built-in drivers often work fine for basic browsing but can bottleneck upload performance compared to the manufacturer’s latest driver.

1. Press Win + X and select Device Manager.
2. Expand Network adapters and right-click your WiFi adapter (e.g., “Intel Wi-Fi 6E AX211” or “Realtek RTL8852BE”).
3. Select Update driver → Search automatically for drivers.
4. If nothing is found, visit the adapter manufacturer’s website directly — Intel, Realtek, Qualcomm, or Broadcom — and download the latest driver manually.

After installing the driver, restart your PC and re-run the speed test.

Step 3: Disable Large Send Offload (LSO)

Large Send Offload is a Windows feature that lets the network adapter handle packet segmentation instead of the CPU — in theory, this improves performance, but in practice it causes upload throttling on many adapters. Disabling it is one of the most reliable fixes for slow WiFi upload on Windows 10 and 11.

1. Open Device Manager and right-click your WiFi adapter.
2. Select Properties → click the Advanced tab.
3. Find Large Send Offload V2 (IPv4) in the property list and set the value to Disabled.
4. Do the same for Large Send Offload V2 (IPv6).
5. Click OK and restart your PC.

This single change has fixed upload speeds for thousands of users on Microsoft’s community forums — it’s worth trying even if everything else looks correct.

Step 4: Turn Off the Killer Prioritization Engine (Dell & Alienware)

If your PC is a Dell, Alienware, or uses an Intel Killer WiFi adapter (common in gaming laptops), the Killer Intelligence Center software may be silently throttling your upload traffic. The Killer Prioritization Engine (KPE) is designed to prioritize gaming traffic, but it frequently misclassifies upload streams as low priority.

1. Open the Killer Intelligence Center app (search for it in Start).
2. Navigate to Settings or the Prioritization section.
3. Toggle off Killer Prioritization Engine.

If you don’t use this software intentionally, you can uninstall it entirely from Settings → Apps — the adapter will still work perfectly with the standard Windows driver.

Step 5: Disable Metered Connection

When a WiFi network is marked as “metered” in Windows, the OS restricts background upload activity to save data. This can appear as slow upload speeds even for foreground apps on some configurations.

1. Go to Settings → Network & Internet → Wi-Fi.
2. Click on your connected network name.
3. Under Metered connection, make sure the toggle is set to Off.

Step 6: Switch to the 5 GHz Band

The 2.4 GHz band is more congested and has lower practical upload throughput than 5 GHz, especially in dense areas. If your PC is connecting to the 2.4 GHz network by default, forcing it to 5 GHz can double or triple your upload speeds.

In Device Manager → adapter Properties → Advanced tab, look for a property called Preferred Band or 802.11 Mode. Set it to 5 GHz or 802.11a/n/ac/ax (anything that excludes the “g” suffix). Alternatively, check that you’re connecting to your router’s 5 GHz SSID in your WiFi settings.

For a full breakdown of band differences, see our guide on 2.4 GHz vs 5 GHz vs 6 GHz WiFi.

Step 7: Reset TCP/IP Stack and Flush DNS

A corrupted network stack can selectively impact upload performance. This reset is safe, takes 30 seconds, and often resolves mysterious asymmetric speed issues:

1. Open Command Prompt as Administrator (search “cmd”, right-click, Run as administrator).
2. Run each command, pressing Enter after each:

netsh int ip reset
netsh winsock reset
ipconfig /flushdns
ipconfig /release
ipconfig /renew

Restart your PC after running all five commands.

Step 8: Check for Background Upload Hogs

Windows Update, OneDrive, Dropbox, backup software, and game launchers like Steam can saturate your upload bandwidth in the background without obvious warnings. To identify culprits:

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Click the Network column header to sort by network usage.
3. Look for any processes sending significant data when you’re not actively uploading anything.

You can pause OneDrive sync from the system tray, defer Windows Update in Settings, and configure Steam to limit upload bandwidth under Steam → Settings → Downloads.

Step 9: Consider a USB WiFi Adapter

If none of the above fixes work, the built-in WiFi adapter on your PC may simply be a low-quality part with limited upload capability. Many budget laptops and desktops ship with 1×1 or 2×2 adapters that top out at 150–300 Mbps theoretical throughput.

A quality USB WiFi 6 adapter — such as the TP-Link Archer TX50UH or ASUS USB-AX56 — costs $30–$60 and will outperform most built-in adapters while giving you a clean driver to work with. For desktop PCs, a PCIe WiFi card like the Intel AX210 is an even better upgrade that brings WiFi 6E and Bluetooth 5.3.

Quick Recap

1. Confirm the problem is isolated to your PC using a phone comparison test
2. Update WiFi adapter driver from the manufacturer’s website
3. Disable Large Send Offload V2 (IPv4 and IPv6) in adapter Advanced settings
4. Disable the Killer Prioritization Engine if present
5. Disable metered connection in WiFi network settings
6. Switch to or force the 5 GHz band
7. Reset TCP/IP stack and flush DNS via Command Prompt
8. Kill background upload processes in Task Manager
9. Upgrade to an external WiFi adapter if needed

For more WiFi troubleshooting, see our guides on reducing WiFi latency and fixing high ping, both of which share root causes with slow upload performance.