diff --git a/README.md b/README.md
index 30d5db8..35e8380 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 # SwiftCommand
 
-![Platform: macOS/Linux](https://img.shields.io/badge/platform-macOS%20%7C%20Linux-orange) ![Swift versions: 5.6](https://img.shields.io/badge/swift-5.6-blue)
+![Platform: macOS/Linux/Windows](https://img.shields.io/badge/platform-macOS%20%7C%20Linux%20%7C%20Windows-orange)
+![Swift versions: 5.6](https://img.shields.io/badge/swift-5.6-blue)
 
 A wrapper around `Foundation.Process`, inspired by Rust's
 `std::process::Command`. This package makes it easy to call command line
diff --git a/Sources/SwiftCommand/Command.swift b/Sources/SwiftCommand/Command.swift
index 8fed60e..4295bd9 100644
--- a/Sources/SwiftCommand/Command.swift
+++ b/Sources/SwiftCommand/Command.swift
@@ -74,7 +74,24 @@ where Stdin: InputSource, Stdout: OutputDestination, Stderr: OutputDestination {
         }
     }
 
-    
+
+#if os(Windows)
+    @inline(__always)
+    private static var pathVariable: String { "Path" }
+    @inline(__always)
+    private static var pathSeparator: Character { ";" }
+    @inline(__always)
+    private static var executableExtension: String { ".exe" }
+#else
+    @inline(__always)
+    private static var pathVariable: String { "PATH" }
+    @inline(__always)
+    private static var pathSeparator: Character { ":" }
+    @inline(__always)
+    private static var executableExtension: String { "" }
+#endif
+
+
     /// The path of the executable file that will be invoked when this command
     /// is spawned.
     ///
@@ -206,15 +223,24 @@ where Stdin: InputSource, Stdout: OutputDestination, Stderr: OutputDestination {
     where Stdin == UnspecifiedInputSource,
           Stdout == UnspecifiedOutputDestination,
           Stderr == UnspecifiedOutputDestination {
-        guard let environmentPath = ProcessInfo.processInfo
-                                               .environment["PATH"] else {
+        let nameWithExtension: String
+        if !Self.executableExtension.isEmpty
+            && !name.hasSuffix(Self.executableExtension) {
+            nameWithExtension = name + Self.executableExtension
+        } else {
+            nameWithExtension = name
+        }
+        
+        guard let environmentPath =
+            ProcessInfo.processInfo.environment[Self.pathVariable] else {
             return nil
         }
 
-        guard let executablePath = environmentPath.split(separator: ":").lazy
+        guard let executablePath =
+            environmentPath.split(separator: Self.pathSeparator).lazy
             .compactMap(FilePath.init(substring:))
-            .map({ $0.appending(name) })
-            .first(where: { 
+            .map({ $0.appending(nameWithExtension) })
+            .first(where: {
                 FileManager.default.isExecutableFile(atPath: $0.string)
             }) else {
             return nil
diff --git a/Sources/SwiftCommand/FileHandle+Async.swift b/Sources/SwiftCommand/FileHandle+Async.swift
index 62bbf7e..b27f38f 100644
--- a/Sources/SwiftCommand/FileHandle+Async.swift
+++ b/Sources/SwiftCommand/FileHandle+Async.swift
@@ -1,6 +1,7 @@
 import Foundation
 
 fileprivate final actor IOActor {
+#if !os(Windows)
     fileprivate func read(
         from fd: Int32,
         into buffer: UnsafeMutableRawBufferPointer
@@ -10,9 +11,6 @@ fileprivate final actor IOActor {
             let read = Darwin.read
 #elseif canImport(Glibc)
             let read = Glibc.read
-#elseif canImport(CRT)
-            let read = CRT._read
-#else
 #error("Unsupported platform!")
 #endif
             let amount = read(fd, buffer.baseAddress, buffer.count)
@@ -29,6 +27,7 @@ fileprivate final actor IOActor {
             }
         }
     }
+#endif
     
     fileprivate func read(
         from handle: FileHandle,
@@ -174,7 +173,9 @@ extension FileHandle {
             fileprivate init(file: FileHandle) {
                 self._buffer = _AsyncBytesBuffer(_capacity: Self.bufferSize)
                 
+#if !os(Windows)
                 let fileDescriptor = file.fileDescriptor
+#endif
                 
                 self._buffer.readFunction = { buf in
                     buf._nextPointer = buf.baseAddress
@@ -186,6 +187,12 @@ extension FileHandle {
                         count: capacity
                     )
                     
+#if os(Windows)
+                    let readSize = try await IOActor.default.read(
+                        from: file,
+                        into: bufPtr
+                    )
+#else
                     let readSize: Int
                     if fileDescriptor >= 0 {
                         readSize = try await IOActor.default.read(
@@ -198,6 +205,7 @@ extension FileHandle {
                             into: bufPtr
                         )
                     }
+#endif
                     
                     buf._endPointer = buf._nextPointer + readSize
                     return readSize