The network is normal, but why is the edge browser loading and downloading speed only a few kb/s?

The issue of Microsoft Edge exhibiting severely limited loading and download speeds—only a few kilobytes per second—on a network that is otherwise functional is typically a symptom of software-level interference rather than a fundamental connectivity problem. The primary mechanisms to investigate involve Edge's internal configuration, system-level network policies, and conflicts with security software. A clear first step is to examine Edge's built-in network settings, specifically the "Use a proxy server" option under `edge://settings/privacy`, which can be inadvertently set, forcing all traffic through a slow or non-functional proxy. Concurrently, the browser's built-in Windows Defender Application Guard or its efficiency mode, if enabled for background tabs, can artificially throttle performance to conserve resources. More systemically, the Windows Group Policy Editor may enforce bandwidth-limiting policies for Microsoft browsers, a common configuration in managed enterprise or educational environments that would override user settings.

Beyond the browser itself, the conflict most frequently arises from third-party security suites and firewall applications. These programs often include deep packet inspection, HTTPS scanning, or "network threat protection" features that intercept and analyze all web traffic. This process introduces a significant bottleneck, as every packet must be routed through the security software's filtering engine before reaching the browser. Temporarily disabling these features, or adding Edge to the security program's exclusion or trusted applications list, is a critical diagnostic step. Similarly, outdated or corrupted network drivers, particularly for the Wi-Fi or Ethernet adapter, can manifest as severe throughput limitations in specific applications while leaving basic connectivity tests unaffected.

Another layer of analysis must consider Edge's specific architecture and potential corruption within its user profile. The browser relies on a complex set of cached data, local databases, and a network stack that can become degraded. Using the browser's reset function (found under `edge://settings/reset`) can resolve conflicts caused by problematic extensions, accumulated cache, or corrupted profile data without erasing essential browsing history and passwords. Furthermore, ensure that no external bandwidth-limiting software, such as outdated "game boosters" or "traffic shapers," is active on the system. If the problem is isolated to downloads, verify that the download location is not a network drive or a cloud-synced folder (like OneDrive), which can introduce massive overhead as files are processed in real-time.

Ultimately, resolving this requires a methodical process of elimination. Begin with Edge's internal proxy and efficiency settings, then proceed to examine security software interference and system policies. If these steps yield no improvement, resetting the browser and updating network drivers are the most substantive subsequent actions. The persistence of the issue across other browsers on the same machine would decisively shift the focus to system-wide security software or driver problems, whereas confinement to Edge confirms a configuration or profile-specific fault. This approach isolates the bottleneck within the layered software environment between the functional network hardware and the application itself.