Documentation

Administrator documentation

A focused reference for installing, configuring, and maintaining Squid Proxy Professional on Windows. Bundled documentation in the product is more detailed; this page covers the essentials.

Installation guide

Run the code-signed Windows installer with administrator privileges. The installer places binaries under C:\Program Files\SquidProxyPro and writable data (configuration, cache, logs) under C:\ProgramData\SquidProxyPro. By default, the Squid service is registered with automatic startup but left stopped until you complete first-time setup.

Recommended steps:

  1. Verify the installer's SHA-256 checksum against the value on the Download page.
  2. Right-click the installer and choose Run as administrator.
  3. Accept the license agreement and choose the install location (defaults are recommended).
  4. Allow the installer to register the Squid service.
  5. Launch the management console from the Start menu when installation completes.

First-time setup

The first time you open the management console, walk through the setup checklist:

  1. Set the visible hostname for the proxy.
  2. Confirm or change the listener port (3128 by default).
  3. Define at least one source-network ACL, for example your internal LAN range.
  4. Apply a default allow rule for that ACL and a deny-all fallback.
  5. Validate the configuration and start the service.

The console validates each change before it's written, and offers to roll back if the service fails to start.

Starting and stopping the Squid service

The Squid service is a standard Windows service named SquidProxyPro. You can control it from the management console (recommended) or from Windows tools.

From PowerShell:

Start-Service  SquidProxyPro
Stop-Service   SquidProxyPro
Restart-Service SquidProxyPro
Get-Service    SquidProxyPro

From Command Prompt:

sc start    SquidProxyPro
sc stop     SquidProxyPro
sc query    SquidProxyPro

The console additionally surfaces recent service failures and last-start exit codes to help you diagnose startup problems.

Configuring browser/client proxy settings

Point clients at the proxy's IP and listener port. Common methods on Windows networks:

  • System-wide proxy: Settings → Network & Internet → Proxy. Set Manual proxy setup to your server IP and port.
  • Group Policy: deploy proxy settings via User Configuration → Preferences → Control Panel Settings → Internet Settings.
  • WPAD/PAC: host a wpad.dat/PAC file and configure clients to auto-detect or use a specific PAC URL.
  • Per-application: configure proxy in browsers or applications that don't honour the system setting (Firefox, some development tools).

Opening Windows Firewall ports

By default, Windows Firewall blocks inbound traffic to the Squid listener. Allow inbound traffic on the configured port for your private/domain profile only:

New-NetFirewallRule -DisplayName "Squid Proxy Professional (3128)" `
  -Direction Inbound `
  -Action Allow `
  -Protocol TCP `
  -LocalPort 3128 `
  -Profile Domain,Private

Replace 3128 with your configured listener port. Avoid opening the port on the Public profile unless you specifically intend the proxy to be reachable from untrusted networks.

Viewing logs

Squid Proxy Professional writes access and cache logs to C:\ProgramData\SquidProxyPro\logs\. Use the management console's log viewer for filtered, paginated browsing, or open the files directly with any text editor.

To tail the access log from PowerShell:

Get-Content "C:\ProgramData\SquidProxyPro\logs\access.log" -Tail 50 -Wait

The console additionally provides quick filters for client IP, response status, and time range.

Backing up configuration

Use the console's Backup action to export configuration, ACLs, and console settings as a single archive. Store the archive alongside the rest of your server configuration in version control or your backup system.

To restore on a new machine, install Squid Proxy Professional, open the console, and use Restore to import the archive. The console will validate the imported configuration before applying it.

Optional: enable automatic backup before changes in the console settings so each apply also writes a timestamped backup.

Troubleshooting

The console's Diagnostics view runs the most common checks (service state, listener port availability, configuration validation, filesystem permissions, firewall rules) and reports concrete next steps. A few common issues:

  • Service won't start. Check the configuration validation result; a syntax error or missing referenced file is the most likely cause.
  • Port already in use. Another service is bound to the same port. Use netstat -ano to identify the process or change the listener port.
  • Clients can't connect. Confirm the firewall rule for the listener port and that clients are pointed at the correct IP.
  • "Access denied" responses. Confirm your ACLs match the client's source network and that the rule chain reaches an allow rule before the deny-all fallback.

Uninstalling

Uninstall from Settings → Apps → Installed apps → Squid Proxy Professional → Uninstall, or from the classic Programs and Features control panel. The uninstaller stops and removes the service, removes program files, and offers to delete data under C:\ProgramData\SquidProxyPro.

If you intend to reinstall and keep your configuration, choose Keep data when prompted, or back up the configuration first.