diff --git a/cli/Cargo.lock b/cli/Cargo.lock
index 18194a3..ecb4aea 100644
--- a/cli/Cargo.lock
+++ b/cli/Cargo.lock
@@ -9,6 +9,7 @@ dependencies = [
  "libc",
  "serde",
  "serde_json",
+ "windows-sys",
 ]
 
 [[package]]
@@ -107,6 +108,79 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
 [[package]]
 name = "zmij"
 version = "1.0.12"
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index ef47f9b..6f36cec 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -12,6 +12,9 @@ serde_json = "1.0"
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
 
+[target.'cfg(windows)'.dependencies]
+windows-sys = { version = "0.52", features = ["Win32_System_Threading", "Win32_Foundation"] }
+
 [profile.release]
 opt-level = 3
 lto = true
diff --git a/cli/src/main.rs b/cli/src/main.rs
index 8eec97e..1f86fe3 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -9,6 +9,14 @@ use std::env;
 use std::fs;
 use std::process::exit;
 
+#[cfg(unix)]
+use libc;
+
+#[cfg(windows)]
+use windows_sys::Win32::Foundation::CloseHandle;
+#[cfg(windows)]
+use windows_sys::Win32::System::Threading::{OpenProcess, PROCESS_QUERY_LIMITED_INFORMATION};
+
 use commands::{gen_id, parse_command, ParseError};
 use connection::{ensure_daemon, send_command};
 use flags::{clean_args, parse_flags};
@@ -36,11 +44,19 @@ fn run_session(args: &[String], session: &str, json_mode: bool) {
                             // Check if session is actually running
                             let pid_path = tmp.join(&name);
                             if let Ok(pid_str) = fs::read_to_string(&pid_path) {
-                                if let Ok(pid) = pid_str.trim().parse::<i32>() {
+                                if let Ok(pid) = pid_str.trim().parse::<u32>() {
                                     #[cfg(unix)]
-                                    let running = unsafe { libc::kill(pid, 0) == 0 };
+                                    let running = unsafe { libc::kill(pid as i32, 0) == 0 };
                                     #[cfg(windows)]
-                                    let running = true; // Simplified for Windows
+                                    let running = unsafe {
+                                        let handle = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, 0, pid);
+                                        if handle != 0 {
+                                            CloseHandle(handle);
+                                            true
+                                        } else {
+                                            false
+                                        }
+                                    };
                                     if running {
                                         sessions.push(session_name.to_string());
                                     }