Windows Clash Setup Walkthrough: Choosing the Right Installer to TUN Mode Pitfalls

Choosing an installer: architecture and build differences

Windows client builds differ in underlying core and interface type, and picking the wrong one will throw off every step that follows. Most mainstream clients are now built on Clash Meta (the mihomo core) and ship with a GUI plus subscription management. You'll typically see three package types: an installer build (an exe that writes to the registry and Start Menu), a portable build (unzip and run, no system changes), and a few variants that bundle a separate driver installer. First check your system architecture — 64-bit Windows 10/11 needs the x64 package, while older machines or ARM-based Windows need the matching build. Installing the wrong architecture usually shows up as the app doing nothing on double-click, or an error saying it's "not a valid Win32 application."

The main difference between the installer and portable builds comes down to permissions and leftovers: the installer build registers a local service to support TUN mode, so uninstalling cleanly requires going through the system's "Uninstall a program" entry. The portable build keeps all config files inside its extracted folder, which makes it easier to move around or run multiple instances — but if you want TUN mode, you'll still need to run it as administrator once to register the driver. For a first install, the installer build is the better pick: the setup flow is more complete and leaves clearer logs for troubleshooting later.

First launch: dealing with SmartScreen and security prompts

The first time you run a freshly downloaded installer, Windows will very likely show a "Windows protected your PC" SmartScreen warning. This is just the default block for new, low-download executables — it has nothing to do with whether the file is actually trustworthy. To proceed, click "More info" in the prompt, then click "Run anyway." If that button doesn't appear, Group Policy or third-party security software has likely tightened SmartScreen settings, and you'll need to temporarily adjust this under Windows Security → App & browser control.

Keep the default install path (usually under your user folder or Program Files). Avoid installing into a deep path containing Chinese characters or special symbols, which can cause encoding issues when some versions read config file paths.

Importing a subscription and verifying basic connectivity

Once the client is installed and open for the first time, import your subscription before touching any other settings — doing things out of order makes it much harder to tell network issues apart from configuration issues. Most GUI clients have a "Subscriptions" or "Profiles" page with a URL field: paste your subscription link and click download, and the client will parse out the node list and rule groups automatically.

1. Paste the subscription URL and download it, then confirm the node list isn't empty and the names match what you expect.
2. On the nodes page, run a manual latency test or select a node, and check that it returns an actual millisecond value rather than a timeout.
3. Don't rush to enable the system proxy yet — first confirm in the client's built-in logs or connections page that it can establish connections normally.
4. Once that checks out, move on to system proxy and mode settings.

If the node list is empty or the download fails at this step, first check whether the subscription link was copied in full or has expired. Subscription format issues aren't the focus of this article, so check other troubleshooting notes on the site for that.

System proxy vs. TUN mode: enabling order and permission requirements

On Windows, there are two ways to actually route your browser and other apps through the proxy, and they work very differently in terms of mechanism and permissions — worth understanding both before choosing.

System proxy mode

This is the most basic method: the client writes an HTTP/HTTPS proxy address (usually 127.0.0.1 plus a port) into Windows' network settings, and any app that respects the system proxy setting will pick it up automatically. It's usually toggled with a "System Proxy" switch in the client UI — once enabled, you'll see the manual proxy address filled in under Settings → Network & Internet → Proxy. This mode doesn't require administrator rights, but it only covers apps that honor the system proxy setting; some apps bypass it and connect directly regardless.

TUN mode

TUN mode sets up a virtual network adapter at the system level and intercepts all traffic (or traffic matching your rules), giving much more complete coverage. But it requires installing a network driver (commonly based on WinDivert or Wintun), so the client must be run as administrator the first time you enable it, and you'll need to approve the driver installation or service confirmation prompt that appears. It's usually toggled via a "TUN Mode" or "Virtual NIC Mode" switch in Settings. Expect a brief network interruption (a few seconds to over ten seconds) the first time you enable it — that's just the virtual adapter initializing and is completely normal.

Auto-start on boot and troubleshooting service install failures

For everyday use, it's worth enabling auto-start so you don't have to manually open the client every time, which would otherwise leave your proxy status inconsistent. Most GUI clients have an "Auto-start on boot" toggle under general settings, which registers a startup entry or scheduled task in the background — no extra steps needed once it's on.

Some clients install an additional background service to support TUN mode (so the virtual adapter can keep running even when no user is logged in), and failures during this service install are the second most common source of errors on Windows. Here's a rundown of typical symptoms and fixes:

If the install keeps failing, try rebooting once before retrying — this rules out most false failures caused by leftover processes or held handles.

Checklist for common pitfalls like port conflicts

Beyond permission and driver issues, the following problems come up frequently during initial Windows setup — listed here together so you can check them off one by one.

• Mixed port already in use: If the local port the client listens on by default (commonly 7890/7891) is already taken by another proxy tool or local service, the client may fail to start or the proxy simply won't work. You can change the listening port in settings, or close whatever else is using that port first.
• System proxy conflicting with browser proxy extensions: If your browser has a standalone proxy extension installed, its settings may override the system proxy, causing browser behavior to not match the client's actual state. During troubleshooting, try temporarily disabling the extension first.
• Virtual adapter conflicting with a local VPN client: If you're also running enterprise VPN software or similar virtual-adapter tools, TUN mode may compete with it over routing priority, showing up as some sites working and others not. Try temporarily disabling one to test the other in isolation.
• Accidentally clicking "Block" on the first firewall prompt: The first time Windows Firewall detects the client trying to access the network, it shows a prompt asking for permission. If you clicked Block by mistake, go to Windows Defender Firewall → Allow an app through firewall and manually check the public/private network permissions for the client.
• Websites still won't load in rule mode: Confirm the current policy mode (rule-based/global/direct) matches what you expect — in rule mode, some sites being routed directly by rule design is normal behavior, not a malfunction.

Working through this order — is the system proxy on → is TUN mode actually active with admin rights → are the port and firewall allowed through → does the policy mode match expectations — covers the vast majority of first-time setup issues on Windows, and the same checklist applies just as well after future updates.