Your internet connection tests slow on your computer — web pages take seconds to load, video buffers constantly, downloads crawl — but other devices on the same network work fine. This tells you the problem is the computer specifically, not the internet service itself. Or maybe all devices are slow, which points to the router, modem, or ISP. Either way, you can diagnose and fix most slow internet problems yourself by working through the causes systematically.
Test your actual speed first
Before troubleshooting, measure the baseline so you know exactly how slow the connection is and whether your fixes help:
Connect the computer directly to the router with an Ethernet cable if possible. Open a browser and go to speedtest.net or fast.com. Run the test and note the download speed, upload speed, and ping
Compare the results to what your ISP plan promises. If you pay for 200 Mbps and the wired test shows 180 Mbps, your internet connection is fine and the problem is elsewhere (Wi-Fi, a specific app, DNS). If the wired test shows 20 Mbps on a 200 Mbps plan, the problem may be the modem, ISP, or the computer Ethernet adapter
Run the same test on Wi-Fi. If the wired speed is normal but Wi-Fi is slow, the problem is your wireless connection specifically
Test on another device (phone, tablet, another computer) on the same network. If all devices are slow, the problem is the router, modem, or ISP. If only your computer is slow, the problem is the computer
Restart the network equipment
This fixes more problems than any other single step:
Power off the modem (unplug it from the wall). Wait 30 seconds. Power it back on and wait for all the lights to stabilize (1 to 2 minutes)
Then power off the router (if separate from the modem). Wait 30 seconds. Power it back on. Wait for it to fully restart (1 to 2 minutes)
The order matters — modem first, then router. The modem needs to establish the connection with the ISP before the router can route traffic through it
Also restart the computer. A fresh boot clears DNS caches, resets network adapters, and closes background processes that may be consuming bandwidth
Fix Wi-Fi specific problems
If your wired connection is fast but Wi-Fi is slow, the wireless link between your computer and router is the bottleneck:
Distance and obstacles: Wi-Fi signal weakens significantly through walls, floors, and large metal objects. A router two rooms away through drywall may provide half the speed or less compared to being in the same room. Move closer to the router as a test — if speed improves dramatically, your normal location has a weak signal
Switch to 5 GHz: Most modern routers broadcast two networks — 2.4 GHz (longer range, slower speed, more interference) and 5 GHz (shorter range, faster speed, less interference). If your computer is connected to the 2.4 GHz network, switch to 5 GHz. Look for your network name with a 5G suffix in the Wi-Fi list, or log into the router to check which band you are connected to
Wi-Fi channel congestion: In apartments and dense neighborhoods, dozens of routers may share the same Wi-Fi channel, causing interference and slow speeds. Log into your router (typically 192.168.1.1 or 192.168.0.1 in a browser) and change the Wi-Fi channel. For 2.4 GHz, channels 1, 6, and 11 are the only non-overlapping options. For 5 GHz, DFS channels (52 to 144) are usually less congested. Many routers have an Auto channel setting that selects the best channel — try it
Wi-Fi adapter driver: An outdated or generic Wi-Fi adapter driver can limit speed and cause disconnects. Open Device Manager, expand Network Adapters, right-click the Wi-Fi adapter, select Update Driver. For the best results, download the latest driver directly from the laptop manufacturer or adapter manufacturer website rather than relying on Windows Update
Disable Wi-Fi power saving: Windows reduces Wi-Fi adapter power to save battery, which can reduce throughput. Open Device Manager, right-click the Wi-Fi adapter, Properties, Power Management tab, uncheck Allow the computer to turn off this device to save power. Also in the Advanced tab, look for a Power Saving Mode or Transmit Power setting and set it to Maximum Performance
DNS optimization
DNS (Domain Name System) translates website names into IP addresses. A slow DNS server makes every website feel slow because each new domain lookup takes extra time before the page even starts loading:
Open Settings, Network and Internet, your connection (Wi-Fi or Ethernet), Hardware Properties, then click Edit next to DNS Server Assignment
Switch to Manual and enter faster DNS servers. Google DNS: 8.8.8.8 and 8.8.4.4. Cloudflare DNS: 1.1.1.1 and 1.0.0.1. Both are typically faster than ISP default DNS servers and more reliable
After changing DNS, open Command Prompt and run ipconfig /flushdns to clear the old DNS cache
Check for bandwidth-consuming processes
Open Task Manager (Ctrl+Shift+Esc), click the Network column to sort by network usage. Any process using significant bandwidth is consuming your internet speed
Common offenders: Windows Update downloading in the background (svchost.exe using network), OneDrive or Google Drive syncing large files, cloud backup software uploading, Steam or game launchers updating games, antivirus software performing cloud lookups
Delivery Optimization: Windows 10 and 11 share update files with other computers over the internet by default, using your upload bandwidth. Open Settings, Windows Update, Advanced Options, Delivery Optimization. Set Allow downloads from other PCs to Local network only or turn it off completely
Open Resource Monitor (search for it in the Start menu), click the Network tab. This shows every process with active network connections and their current bandwidth usage — more detailed than Task Manager
Reset the network stack
Corrupted network configuration can cause slow speeds and connection problems. Resetting it forces Windows to rebuild everything from scratch:
Open Command Prompt as administrator and run these commands one at a time:
netsh winsock reset — resets the Windows Sockets catalog
netsh int ip reset — resets TCP/IP settings
ipconfig /release — releases the current IP address
ipconfig /flushdns — clears the DNS cache
ipconfig /renew — obtains a new IP address from the router
Restart the computer after running these commands
Ethernet adapter issues
Cable quality: A damaged Ethernet cable or one that is Cat5 (limited to 100 Mbps) instead of Cat5e or Cat6 (supports 1 Gbps) bottlenecks your connection. If your wired speed is stuck at exactly 100 Mbps, the cable or one of the ports is limited to Fast Ethernet. Replace the cable with a Cat5e or Cat6 cable
Check link speed: Open Settings, Network and Internet, Ethernet, and look for the link speed. It should show 1 Gbps for a gigabit connection. If it shows 100 Mbps, the cable, router port, or adapter is limiting the connection
Adapter driver: Like Wi-Fi adapters, Ethernet adapter drivers can be outdated or buggy. Update through Device Manager or download the latest from the manufacturer website. Intel and Realtek are the two most common Ethernet chipset manufacturers
Malware consuming bandwidth
Some malware uses your internet connection to send spam, participate in botnets, or mine cryptocurrency with your bandwidth. If network usage in Task Manager shows significant activity when you are not doing anything online, run a full scan with Windows Defender and Malwarebytes
Check your router admin panel for connected devices. If you see devices you do not recognize, someone may be using your Wi-Fi. Change the Wi-Fi password and enable WPA3 or WPA2 encryption
Router and ISP issues
Router age: Routers older than four to five years may not support current Wi-Fi standards (Wi-Fi 5 or 6) and their processors struggle with many simultaneous devices. If your router is old and you have upgraded your internet plan, the router itself may be the bottleneck
ISP throttling: Some ISPs reduce speed during peak hours or when you exceed a data cap. Run speed tests at different times of day to check for patterns. If speed is consistently slow during evenings but fast at 3 AM, this suggests congestion at the ISP level
Modem compatibility: If you use your own modem instead of the ISP rental, make sure it supports the speed tier you pay for. An older DOCSIS 3.0 modem may not achieve the speeds of a DOCSIS 3.1 plan
Professional network diagnosis
If you have tried these steps and your internet is still slow on your computer, Luxurious Computers can perform a full network diagnosis — testing your adapter hardware, checking for driver and configuration issues, analyzing Wi-Fi signal quality, and identifying bandwidth consumers — to find and fix the exact cause of the slowdown.