Your PC Wi-Fi is slow.
Your phone Wi-Fi is fine. Same room.
When every other device in the same spot works fine and only one device crawls, the network isn't the variable. The device is. Eight checks, ordered by how often they turn out to be the cause.
The fingerprint
This article applies if all three of these are true:
- One specific device — usually a desktop PC or an older laptop — has terrible Wi-Fi: low throughput, dropped connections, or both.
- Other devices in the same physical location work fine. Same router. Same room. Same band.
- Restarting the router doesn't help. Restarting the slow device sometimes helps for a few minutes, then it degrades again.
If that's the picture, your router and your ISP are not the problem. The router is doing its job — your phone and tablet and smart TV are all proof of that. The problem is on the device that's slow, and it's almost always one of eight specific things.
A note before the checklist: the diagnostic for per-device Wi-Fi problems looks completely different from "my whole house Wi-Fi is slow." Don't chase router settings here. That's a different article.
The 8 checks (in order of frequency)
Power management is throttling the Wi-Fi adapter
Windows: Device Manager → Network Adapters → your Wi-Fi adapter → Properties → Power Management tab. macOS: System Settings → Battery → Options. Linux: rfkill list / iwconfig power.By default, Windows lets the OS turn off the Wi-Fi radio to save power. On a desktop that never disconnects from wall power, this is pointless. On a laptop, it's aggressive — the radio downshifts to lower bands and disables MIMO when the OS thinks it's idle. The slow-Wi-Fi-after-it-sits-for-a-while pattern is almost always this.
Uncheck 'Allow the computer to turn off this device to save power.' Reboot. Run a speed test on the laptop with the lid open and the device actively in use.
Most common cause on laptops. Often the first thing the device's slow-Wi-Fi history comes from.
The device is silently stuck on 2.4 GHz when 5 GHz is available
Windows: Settings → Network → Wi-Fi → Properties → look for 'Network band.' macOS: Option-click the Wi-Fi icon in the menu bar, then look at 'Channel.' iOS / Android: in the network details screen on most modern OSes.2.4 GHz penetrates walls better but tops out around 100–150 Mbps in practice and is shared with every microwave, Bluetooth device, and neighbor's network in range. 5 GHz delivers 400–900 Mbps in the same room but is dropped silently by older adapters or by routers configured with band steering that's too conservative.
If the band shows 2.4 GHz and your router broadcasts 5 GHz, forget the network on the slow device and rejoin. Some routers split the SSIDs (NETWORK and NETWORK_5G) — connect explicitly to the 5G one.
Very common on older PCs and laptops where the Wi-Fi card defaults to 2.4 GHz for compatibility.
The Wi-Fi card is an older generation than the phone you're comparing it to
Windows: Device Manager → Network Adapters → look at the adapter model. macOS: System Information → Network → Wi-Fi.A 2018 laptop with an Intel 7265 Wi-Fi card (802.11ac, 2x2) caps around 600 Mbps under perfect conditions and 200–300 Mbps in practice. A 2023 phone with Wi-Fi 6 will run circles around it on the same router. The phone isn't faster than the laptop's plan — the phone is faster than the laptop's hardware.
If the adapter is older than 2020 and your router supports Wi-Fi 6 or 6E, the laptop is structurally capped at the older standard. No software fix bridges this gap.
Common on laptops 4+ years old, custom desktops with old PCIe Wi-Fi cards.
Outdated driver — particularly after a Windows update
Windows: Device Manager → Network Adapters → right-click → Update Driver. Also check the OEM's site (Intel, Killer, Realtek) directly — Windows Update sometimes ships older drivers than the vendor.Wi-Fi driver regressions are surprisingly common after major OS updates. A laptop that worked fine yesterday and runs at 50 Mbps today often has a freshly-installed driver that broke band negotiation, channel selection, or MIMO.
Note the current driver version. Visit the laptop OEM's support page (Dell, HP, Lenovo) and download the latest Wi-Fi driver. Install. Reboot.
Strong signal if the slowness started suddenly and correlates with a Windows update.
The antenna position on a desktop tower is blocking the radio
Physical inspection of the tower. Look at where the Wi-Fi antennas attach to the back — most desktop Wi-Fi cards have screw-on external antennas.A desktop PC's Wi-Fi card antennas are often pointed at the inside of a metal case panel, or hidden behind a desk. Phones win signal strength comparisons because their antennas are at the surface of the device — not buried behind sheet steel.
If the antennas are detachable, point them straight up. If they're cabled, run them on top of the desk rather than behind the tower. A 10-second physical adjustment that often recovers 30–50% throughput.
Almost universal on prebuilt desktops; common on custom desktops with stock motherboard Wi-Fi.
Bluetooth interference on the 2.4 GHz band
Anywhere a Bluetooth device is paired to the same machine that has Wi-Fi trouble.Bluetooth and 2.4 GHz Wi-Fi share spectrum. Both protocols cooperate via 'coexistence' logic, but on cheap combo cards (where Bluetooth and Wi-Fi are on the same chip), the radios can't transmit simultaneously. Active Bluetooth — especially Bluetooth audio — will visibly throttle Wi-Fi throughput on the same machine.
Temporarily disable Bluetooth. Run a speed test. If throughput jumps, your card is on a combo chip and Bluetooth is the constraint. Workaround: use 5 GHz Wi-Fi (separate radio path) or move Bluetooth audio to wired headphones.
Significant on laptops with Intel combo cards. Rarely the only cause, but often contributes.
USB Wi-Fi dongle plugged into a USB 2.0 port
USB Wi-Fi adapters specifically. Check which port they're in.A USB 3.0 or 3.1 Wi-Fi adapter plugged into a USB 2.0 port caps at 480 Mbps and often less due to USB overhead. Worse: USB 3.0 ports emit broadband RF noise on the 2.4 GHz band, which can interfere with a 2.4 GHz Wi-Fi adapter plugged right next to them.
Verify the dongle is in a USB 3.0+ port (usually blue or marked with SS). If you're on 2.4 GHz Wi-Fi and have a USB 3 hub nearby, try a USB extension cable to physically separate the dongle from the hub.
Very common on desktops with USB Wi-Fi adapters as the only Wi-Fi solution.
Channel congestion on the 5 GHz band, especially DFS channels
Router admin panel: Wi-Fi → 5 GHz channel selection.Most routers auto-select 5 GHz channels. In a dense apartment building, the non-DFS channels (36, 40, 44, 48, 149, 153, 157, 161) are often saturated by neighbors. DFS channels (52–144) are typically clearer but require the router to silently switch off when it detects radar — which causes intermittent drops on devices that don't tolerate the switch well.
Use a Wi-Fi scanner app (NetSpot, WiFi Analyzer on Android) to see which channels are busy in your space. If your router is on a DFS channel and the slow device handles it poorly, set the router to a fixed non-DFS channel. If non-DFS channels are saturated, accept the DFS trade-off or move closer to the router.
Apartment dwellers in dense buildings. Rare in single-family homes.
How to triage faster
If you want to skip the eight-step walk, two tests cut to the answer faster:
The hotspot test. Turn on your phone's hotspot. Connect the slow PC to the phone. Run a speed test. If the PC suddenly gets fast on the hotspot, the PC's Wi-Fi radio is fine — something in your home network configuration is rejecting it. (Less common but worth ruling out.)
The USB Wi-Fi test. Borrow or buy a USB Wi-Fi 6 adapter (affiliate), plug it into the slow PC, and connect through that instead of the built-in card. If throughput is suddenly normal, the built-in adapter is the problem. The fix is to replace it — cheap as a USB dongle, slightly more expensive as a PCIe replacement like the Intel AX210 (affiliate) for desktops.
The signal hiding in your speed-test screenshot
Most users who post about this on r/HomeNetworking screenshot the speed-test result and focus on the big number — 4 Mbps or 38 Mbps or whatever's terrible. The diagnostic gold is usually two lines below, in the loaded-latency section (Ookla, Cloudflare, and similar tests all report it).
If the loaded RTT under upload is 600 ms or more — sometimes approaching a full second — that's not just slow Wi-Fi. That's bufferbloat on a marginal Wi-Fi link, and the bandwidth number you're upset about is downstream of that. The same checklist applies, but seeing the loaded RTT separately tells you the radio is queuing packets it can't send, not that the link is being capped by something else.
Once you've fixed the radio, the loaded RTT should drop back to two-digit territory. Verify it with the StabilityPulse stability test — it'll measure jitter and loaded latency alongside throughput so you know the Wi-Fi recovery is real, not just a transient.
When the answer is just 'replace the card'
If you're on a 2018-or-older laptop with an integrated Intel 7265 or 8265 card and your router is Wi-Fi 6, no amount of tuning will get you to gigabit. The card physically can't negotiate the higher rates. Spending an hour adjusting power management isn't going to bridge a generation gap.
Laptops: the integrated card is usually replaceable on full-size laptops (open the back panel, swap the M.2 module). On Ultrabooks where the card is soldered, your only option is a USB Wi-Fi adapter — which is, ironically, often faster than the soldered card by 2026 standards.
Desktops: a PCIe Wi-Fi 6E card (Intel AX210 or similar) (affiliate) drops in for under $40 and includes the antenna kit. It's the most cost-effective fix for any desktop with stock or old Wi-Fi.
What this article doesn't cover
If all your devices have bad Wi-Fi in a particular room — not just one — the diagnostic is completely different. That's a router placement, mesh coverage, or channel congestion problem, and the fingerprint doesn't apply. We'll cover that one in a separate piece (mesh oversaturation in particular is a surprisingly common case where adding more mesh nodes makes Wi-Fi worse, not better).
If your Wi-Fi is fine but your internet is slow everywhere, that's also a different article — the router-CPU acceleration guide covers the most common shape of that one.