What causes "Failed to kill the process" in rustdesk/rustdesk?

Re-run the operation from an elevated (administrator) process

Failed to kill the process

Error message

Failed to kill the process

What it means

After the name check passes, `process.kill()` (sysinfo) is called; if it returns false the process could not be terminated and this error is raised. Common underlying causes are insufficient privileges (the process runs elevated or as another user) or the process already exiting between the snapshot and the kill call.

Source

Thrown at src/platform/windows.rs:3790

        }
        return Ok(None);
    };
    Ok(Some(get_msi_uninstall_subkey(&product_code)?))
}

// Double confirm the process name
fn kill_process_by_pids(name: &str, pids: Vec<Pid>) -> ResultType<()> {
    let name = name.to_lowercase();
    let s = System::new_all();
    // No need to check all names of `pids` first, and kill them then.
    // It's rare case that they're not matched.
    for pid in pids {
        if let Some(process) = s.process(pid) {
            if process.name().to_lowercase() != name {
                bail!("Failed to kill the process, the names are mismatched.");
            }
            if !process.kill() {
                bail!("Failed to kill the process");
            }
        } else {
            bail!("Failed to kill the process, the pid is not found");
        }
    }
    Ok(())
}

pub fn handle_custom_client_staging_dir_before_update(
    custom_client_staging_dir: &PathBuf,
) -> ResultType<()> {
    let Some(current_exe_dir) = std::env::current_exe()
        .ok()
        .and_then(|p| p.parent().map(|p| p.to_path_buf()))
    else {
        bail!("Failed to get current exe directory");
    };

View on GitHub (pinned to 91c9fccbb0)

Solutions

Re-run the operation from an elevated (administrator) process
Verify the process is still alive and retry the kill
Use `taskkill /f /pid N` manually to see the OS-level error (e.g. Access denied)

Example fix

// before
kill_processes(&pids, name)?;
// after: elevate first
if !is_elevated() { request_elevation()?; }
kill_processes(&pids, name)?;

Defensive patterns

Strategy: retry

Validate before calling

let can_kill = pids.iter().all(|p| sys.process(*p)
    .map_or(false, |pr| pr.name().to_lowercase() == name));
if !can_kill || !is_elevated() { /* elevate before calling kill */ }

Try / catch

if let Err(e) = kill_processes(&pids, name) {
    if e.to_string() == "Failed to kill the process" {
        request_elevation()?;
        kill_processes(&pids, name)?;
    } else { return Err(e); }
}

Prevention

Run kill operations from an elevated process
Do not kill processes owned by other users/sessions
Expect kill() to fail on already-exiting processes and retry once

When it happens

Trigger: Calling the kill helper with a valid pid whose name matches, but sysinfo's `kill()` fails: target is elevated/protected, owned by another session, or terminated concurrently.

Common situations: Trying to kill an unelevated RustDesk instance's elevated counterpart; killing a service process without admin rights; antivirus protecting the process.

Understand the failure class

Background: "You do not have permission" / 403 Forbidden errors: authenticated but not allowed — causes and fixes across open-source libraries — this error's family across 31 libraries.

Related errors

AI-assisted analysis of rustdesk/rustdesk@91c9fccbb0 (2026-09-10). Data as JSON: /api/errors/9528f37495460db5. Report an issue: GitHub.