diff --git a/genkit-tools/cli/src/utils/runtime-detector.ts b/genkit-tools/cli/src/utils/runtime-detector.ts
index 63f104563d..b0fc861a71 100644
--- a/genkit-tools/cli/src/utils/runtime-detector.ts
+++ b/genkit-tools/cli/src/utils/runtime-detector.ts
@@ -124,7 +124,10 @@ export function detectRuntime(): RuntimeInfo {
   if (hasBunVersion || execMatchesBun || argv0MatchesBun) {
     // Check if this is a Bun-compiled binary
     // Bun compiled binaries have virtual paths like /$bunfs/root/...
-    if (argv1 && argv1.startsWith('/$bunfs/')) {
+    if (
+      argv1 &&
+      (argv1.startsWith('/$bunfs/') || /^[A-Za-z]:[\\/]+~BUN[\\/]+/.test(argv1))
+    ) {
       // This is a Bun-compiled binary
       type = RUNTIME_COMPILED;
       scriptPath = undefined;
diff --git a/genkit-tools/cli/src/utils/spawn-config.ts b/genkit-tools/cli/src/utils/spawn-config.ts
index 28b52661a2..b4e0a89400 100644
--- a/genkit-tools/cli/src/utils/spawn-config.ts
+++ b/genkit-tools/cli/src/utils/spawn-config.ts
@@ -38,7 +38,10 @@ export interface SpawnConfig {
  */
 export async function validateExecutablePath(path: string): Promise<boolean> {
   try {
-    await access(path, constants.F_OK | constants.X_OK);
+    // Remove surrounding quotes if present (handle quotation)
+    const normalizedPath =
+      path.startsWith('"') && path.endsWith('"') ? path.slice(1, -1) : path;
+    await access(normalizedPath, constants.F_OK | constants.X_OK);
     return true;
   } catch {
     return false;
@@ -91,7 +94,7 @@ export function buildServerHarnessSpawnConfig(
     throw new Error('Log path is required');
   }
 
-  const command = runtime.execPath;
+  let command = runtime.execPath;
   let args: string[];
 
   if (runtime.type === 'compiled-binary') {
@@ -112,6 +115,12 @@ export function buildServerHarnessSpawnConfig(
     shell: runtime.platform === 'win32',
   };
 
+  // Handles spaces in the command and arguments on Windows
+  if (runtime.platform === 'win32') {
+    command = `"${command}"`;
+    args = args.map((arg) => `"${arg}"`);
+  }
+
   return {
     command,
     args,
diff --git a/genkit-tools/cli/tests/utils/spawn-config_test.ts b/genkit-tools/cli/tests/utils/spawn-config_test.ts
index 872eb37da0..a84c657442 100644
--- a/genkit-tools/cli/tests/utils/spawn-config_test.ts
+++ b/genkit-tools/cli/tests/utils/spawn-config_test.ts
@@ -79,12 +79,12 @@ describe('spawn-config', () => {
           mockLogPath
         );
 
-        expect(config.command).toBe('C:\\Program Files\\nodejs\\node.exe');
+        expect(config.command).toBe('"C:\\Program Files\\nodejs\\node.exe"');
         expect(config.args).toEqual([
-          'C:\\Users\\dev\\AppData\\Roaming\\npm\\node_modules\\genkit-cli\\dist\\bin\\genkit.js',
-          SERVER_HARNESS_COMMAND,
-          '4000',
-          '/path/to/devui.log',
+          '"C:\\Users\\dev\\AppData\\Roaming\\npm\\node_modules\\genkit-cli\\dist\\bin\\genkit.js"',
+          '"' + SERVER_HARNESS_COMMAND + '"',
+          '"4000"',
+          '"/path/to/devui.log"',
         ]);
         expect(config.options.shell).toBe(true); // Shell enabled on Windows
       });
@@ -180,7 +180,7 @@ describe('spawn-config', () => {
           mockLogPath
         );
 
-        expect(config.command).toBe('C:\\Program Files\\Bun\\bun.exe');
+        expect(config.command).toBe('"C:\\Program Files\\Bun\\bun.exe"');
         expect(config.options.shell).toBe(true);
       });
     });
@@ -227,7 +227,7 @@ describe('spawn-config', () => {
           mockLogPath
         );
 
-        expect(config.command).toBe('C:\\Tools\\genkit.exe');
+        expect(config.command).toBe('"C:\\Tools\\genkit.exe"');
         expect(config.options.shell).toBe(true);
       });