Full Windows Clash Setup: Client Selection, Config Import, and Common Pitfalls

DOC-02

Install and authorize: from download to a working UI

After downloading the installer, double-clicking it will trigger Windows SmartScreen's "Unknown publisher" warning — this is normal digital-signature gatekeeping, and clicking "More info -> Run anyway" lets you proceed. The install itself has no special options to worry about; the default path is fine. Avoid installing into a path with non-ASCII characters or spaces, since some versions have path-parsing quirks.

1. Run the installer and follow the prompts. If a firewall authorization prompt appears on first launch, choose "Allow access" (check both public and private networks) — otherwise the proxy's listening port may get blocked by the system firewall.
2. If the client includes TUN mode, enabling it for the first time will request installation of a virtual network adapter driver. You'll need to click "Yes" on the UAC prompt to authorize it — skipping this step will leave TUN mode permanently showing as failed to start.
3. Once in the main interface, check the app version and core version to confirm you're on the latest stable release — older installers may carry already-fixed known issues.

On some corporate machines or systems with strict domain policies, user-level driver installation may be blocked entirely. In that case TUN mode simply can't be enabled, and falling back to system proxy mode is the only realistic option — there's no point chasing driver-signature issues in this scenario.

DOC-03

Subscription import and initial connectivity check

After installation, the core task is importing your subscription link. Most clients provide an input field on the "Subscription," "Profile," or "Config" page — paste the URL and click download. After importing, confirm three things: the node list loaded correctly, the subscription has an auto-update interval set, and the currently active profile is the one you just imported (clients sometimes keep an old test profile around, which can be used by mistake).

Common subscription import troubleshooting order:
1. Can the subscription URL itself be opened or downloaded directly in a browser (checks whether the link is dead)
2. Does the client correctly recognize it as a Clash / mihomo format config (not v2ray format)
3. Does the node count after import match what you expected
4. Manually test latency on one node — does it return an actual millisecond value instead of timing out

Once the node list loads correctly, go to "Test Latency" or click the speed-test icon next to an individual node, and confirm at least some nodes fall in a reasonable range (typically tens to a few hundred milliseconds — anything over 3000ms or showing a flat timeout is likely unusable). If every node times out, check your machine's basic network connectivity first, then verify whether the original subscription link has expired.

Once nodes are confirmed working, turn on the system proxy toggle (usually labeled "System Proxy" or "Set as system proxy" in the client UI). This points Windows' network proxy settings at your local listening port (commonly 7890 or similar). To verify, open any browser and visit a site, or check whether traffic stats on the client's home page start showing data — either response confirms the proxy chain is working.

DOC-04

Handling antivirus false positives

Because Clash-family clients intercept network traffic, install virtual adapter drivers, and use multi-process communication, they can trigger behavior-analysis engines in some antivirus products and get flagged as suspicious — heuristic detection in certain regional antivirus tools and some enterprise security suites is especially sensitive to this. This is a pattern-matching result on specific behaviors, not evidence that the program itself is problematic — but you should still handle it carefully rather than blindly disabling all protection.

• First identify what's actually being flagged: is the installer itself being blocked, or is it being quarantined during runtime by real-time monitoring — these require different fixes.
• If the installer is blocked, find the corresponding record in the antivirus quarantine or log and choose "Trust" or "Allow," rather than disabling the antivirus entirely before installing.
• If it's quarantined at runtime, add the client's install directory to the antivirus trust list (allowlist/exclusions) — usually found under "Security Settings -> Trusted Zone -> Add File/Folder."
• On corporate machines where security software is centrally managed by IT and you don't have permission to change policy, request an exception from your administrator instead of trying to work around detection with tools.

DOC-05

Troubleshooting port conflicts

The Clash core listens on several ports by default: an HTTP/mixed proxy port (commonly 7890), a Socks5 port, an external controller port (commonly 9090), and so on. If any of these ports are already in use, the client will error out or show the service as not running when starting the core. Port conflicts commonly show up when multiple proxy tools are installed at once, a previous Clash process didn't fully exit, or some download manager is occupying a nearby port range.

The debugging approach is to identify the conflicting port number first, then locate the process holding it:

Open Command Prompt (run as administrator) and run:
netstat -ano | findstr "7890"

The last column in the output is the PID (process ID). Open Task Manager's "Details"
tab, sort by PID, and find the matching process name to confirm whether it's a leftover
old Clash process.

If it turns out to be a leftover old process, end it in Task Manager and restart the client to recover. If a different, actively-used program is occupying the default port, the simpler fix is to change the listening port in the client's settings to a free value (e.g., 7891), avoiding a long-term standoff over the same port with another tool. After changing the port, be sure to check that the port number in your system proxy settings has also been updated — a mismatch there will leave the proxy toggle showing "on" while it's actually not working.

DOC-06

Common reasons startup-on-boot fails

Many users enable "Launch on system startup" in the client settings, only to find it doesn't kick in after a reboot. The common causes fall into a few categories.

1. Startup-on-boot relies on a Windows startup entry (a registry key or a shortcut in the Startup folder). If you have a third-party startup manager or a "lightweight optimizer" utility installed, it may have removed that entry — you'll need to re-add it to the optimizer's allowlist.
2. Some clients need administrator privileges to launch on boot. If your account's UAC policy is strict, silent startup may get blocked by the system — try manually creating a logon-triggered task set to run with the highest privileges in Task Scheduler.
3. If the client exited abnormally the last time it closed (for example, a forced process kill instead of a normal exit), the stored startup-on-boot state in some versions may get corrupted. Toggling the startup switch off and back on in settings usually fixes this.
4. When a laptop resumes from "Fast Startup" or hibernation rather than doing a full cold boot, some startup entries won't re-trigger — this is a system mechanism, not a client issue. If you suspect this is the cause, do a full shutdown and restart once to confirm.

DOC-07

Verification differences: system proxy vs. TUN mode

System proxy mode only affects applications that honor the system proxy setting. Most browsers and mainstream software read this setting, but some apps with their own independent network stack (certain games, command-line tools, some messaging clients) don't — leading to "the client shows the proxy is on, but this program still connects directly." That's not a misconfiguration; it's an inherent coverage limit of system proxy mode.

TUN mode intercepts all traffic at the network layer, so in theory there's no such coverage gap — but the tradeoff is that it requires virtual adapter driver authorization, some security software is more sensitive to virtual adapter behavior, and it can conflict with routing when running alongside certain VPN clients. To verify TUN mode is working, check the client's traffic stats page for a continuous flow of data, or use a command-line tool to check whether the current network interface list includes the newly added virtual adapter device.

DOC-08

Profile updates and managing multiple configs

Subscription profiles usually have an auto-update interval set (e.g., every 24 hours), but in some cases auto-update can silently fail due to network fluctuations, leaving the node list stale for a long time — resulting in "all nodes are actually dead but the UI shows nothing wrong." It's worth manually clicking the subscription's "Update now" button periodically, especially when connectivity feels noticeably worse than usual.

If you maintain multiple subscriptions or custom rule configs long-term, give each profile a clear name and note its source, to avoid mixing up profiles and accidentally using a stale one. Most clients support importing, exporting, and locally backing up profiles — when reinstalling the OS or switching devices, you can export the current profile and import it into the new environment instead of setting everything up by hand again.