diff --git a/src/platform.ts b/src/platform.ts
index 706c9f56e2..360fea1613 100644
--- a/src/platform.ts
+++ b/src/platform.ts
@@ -148,7 +148,7 @@ export class PowerShellExeFinder {
 
         // Also show any additionally configured PowerShells
         // These may be duplicates of the default installations, but given a different name.
-        for (const additionalPwsh of this.enumerateAdditionalPowerShellInstallations()) {
+        for await (const additionalPwsh of this.enumerateAdditionalPowerShellInstallations()) {
             if (await additionalPwsh.exists()) {
                 yield additionalPwsh;
             } else if (!additionalPwsh.suppressWarning) {
@@ -230,7 +230,7 @@ export class PowerShellExeFinder {
      * Iterates through the configured additional PowerShell executable locations,
      * without checking for their existence.
      */
-    private *enumerateAdditionalPowerShellInstallations(): Iterable<IPossiblePowerShellExe> {
+    private async *enumerateAdditionalPowerShellInstallations(): AsyncIterable<IPossiblePowerShellExe> {
         for (const versionName in this.additionalPowerShellExes) {
             if (Object.prototype.hasOwnProperty.call(this.additionalPowerShellExes, versionName)) {
                 let exePath: string | undefined = utils.stripQuotePair(this.additionalPowerShellExes[versionName]);
@@ -245,7 +245,11 @@ export class PowerShellExeFinder {
 
                 // Always search for what the user gave us first, but with the warning
                 // suppressed so we can display it after all possibilities are exhausted
-                yield new PossiblePowerShellExe(exePath, ...args);
+                let pwsh = new PossiblePowerShellExe(exePath, ...args);
+                if (await pwsh.exists()) {
+                    yield pwsh;
+                    continue;
+                }
 
                 // Also search for `pwsh[.exe]` and `powershell[.exe]` if missing
                 if (this.platformDetails.operatingSystem === OperatingSystem.Windows) {
@@ -253,16 +257,32 @@ export class PowerShellExeFinder {
                     if (!exePath.endsWith("pwsh.exe") && !exePath.endsWith("powershell.exe")) {
                         if (exePath.endsWith("pwsh") || exePath.endsWith("powershell")) {
                             // Add extension if that was missing
-                            yield new PossiblePowerShellExe(exePath + ".exe", ...args);
+                            pwsh = new PossiblePowerShellExe(exePath + ".exe", ...args);
+                            if (await pwsh.exists()) {
+                                yield pwsh;
+                                continue;
+                            }
                         }
                         // Also add full exe names (this isn't an else just in case
                         // the folder was named "pwsh" or "powershell")
-                        yield new PossiblePowerShellExe(path.join(exePath, "pwsh.exe"), ...args);
-                        yield new PossiblePowerShellExe(path.join(exePath, "powershell.exe"), ...args);
+                        pwsh = new PossiblePowerShellExe(path.join(exePath, "pwsh.exe"), ...args);
+                        if (await pwsh.exists()) {
+                            yield pwsh;
+                            continue;
+                        }
+                        pwsh = new PossiblePowerShellExe(path.join(exePath, "powershell.exe"), ...args);
+                        if (await pwsh.exists()) {
+                            yield pwsh;
+                            continue;
+                        }
                     }
                 } else if (!exePath.endsWith("pwsh")) {
                     // Always just 'pwsh' on non-Windows
-                    yield new PossiblePowerShellExe(path.join(exePath, "pwsh"), ...args);
+                    pwsh = new PossiblePowerShellExe(path.join(exePath, "pwsh"), ...args);
+                    if (await pwsh.exists()) {
+                        yield pwsh;
+                        continue;
+                    }
                 }
 
                 // If we're still being iterated over, no permutation of the given path existed so yield an object with the warning unsuppressed
diff --git a/test/core/platform.test.ts b/test/core/platform.test.ts
index 299e125626..0953379639 100644
--- a/test/core/platform.test.ts
+++ b/test/core/platform.test.ts
@@ -18,10 +18,20 @@ import { stripQuotePair } from "../../src/utils";
 const platformMock = rewire("../../src/platform");
 
 // eslint-disable-next-line @typescript-eslint/require-await
-async function fakeCheckIfFileOrDirectoryExists(targetPath: string | vscode.Uri): Promise<boolean> {
+async function fakeCheckIfFileExists(targetPath: string | vscode.Uri): Promise<boolean> {
     try {
-        fs.lstatSync(targetPath instanceof vscode.Uri ? targetPath.fsPath : targetPath);
-        return true;
+        const stat = fs.lstatSync(targetPath instanceof vscode.Uri ? targetPath.fsPath : targetPath);
+        return stat.isFile();
+    } catch {
+        return false;
+    }
+}
+
+// eslint-disable-next-line @typescript-eslint/require-await
+async function fakeCheckIfDirectoryExists(targetPath: string | vscode.Uri): Promise<boolean> {
+    try {
+        const stat = fs.lstatSync(targetPath instanceof vscode.Uri ? targetPath.fsPath : targetPath);
+        return stat.isDirectory();
     } catch {
         return false;
     }
@@ -33,8 +43,8 @@ async function fakeReadDirectory(targetPath: string | vscode.Uri): Promise<strin
 }
 
 const utilsMock = {
-    checkIfFileExists: fakeCheckIfFileOrDirectoryExists,
-    checkIfDirectoryExists: fakeCheckIfFileOrDirectoryExists,
+    checkIfFileExists: fakeCheckIfFileExists,
+    checkIfDirectoryExists: fakeCheckIfDirectoryExists,
     readDirectory: fakeReadDirectory,
     stripQuotePair: stripQuotePair
 };
@@ -467,18 +477,11 @@ if (process.platform === "win32") {
                 isOS64Bit: true,
                 isProcess64Bit: true,
             },
-            environmentVars: {},
-            // Note that for each given path, we expect:
-            // 1. The path as-is.
-            // 2. Any expected permutations of the path (for example, with a tilde or folder expanded, and/or '.exe' added).
-            // 3. The path as-is again (in order for a warning to be displayed at the correct time).
-            // An improvement here would be to check the suppressWarning field, but it's not currently exposed.
+            environmentVars: {
+                "USERNAME": "test",
+                "USERPROFILE": "C:\\Users\\test",
+            },
             expectedPowerShellSequence: [
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
-                    displayName: "pwsh",
-                    supportsProperArguments: true
-                },
                 {
                     exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
                     displayName: "pwsh",
@@ -489,86 +492,21 @@ if (process.platform === "win32") {
                     displayName: "pwsh-tilde",
                     supportsProperArguments: true
                 },
-                {
-                    exePath: path.join(os.homedir(), "pwsh", "pwsh.exe"),
-                    displayName: "pwsh-tilde",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh",
-                    displayName: "pwsh-no-exe",
-                    supportsProperArguments: true
-                },
                 {
                     exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
                     displayName: "pwsh-no-exe",
                     supportsProperArguments: true
                 },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh\\pwsh.exe",
-                    displayName: "pwsh-no-exe",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh\\powershell.exe",
-                    displayName: "pwsh-no-exe",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh",
-                    displayName: "pwsh-no-exe",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\",
-                    displayName: "pwsh-folder",
-                    supportsProperArguments: true
-                },
                 {
                     exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
                     displayName: "pwsh-folder",
                     supportsProperArguments: true
                 },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\powershell.exe",
-                    displayName: "pwsh-folder",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\",
-                    displayName: "pwsh-folder",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh",
-                    displayName: "pwsh-folder-no-slash",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh.exe",
-                    displayName: "pwsh-folder-no-slash",
-                    supportsProperArguments: true
-                },
                 {
                     exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
                     displayName: "pwsh-folder-no-slash",
                     supportsProperArguments: true
                 },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\powershell.exe",
-                    displayName: "pwsh-folder-no-slash",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh",
-                    displayName: "pwsh-folder-no-slash",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
-                    displayName: "pwsh-single-quotes",
-                    supportsProperArguments: true
-                },
                 {
                     exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
                     displayName: "pwsh-single-quotes",
@@ -579,13 +517,15 @@ if (process.platform === "win32") {
                     displayName: "pwsh-double-quotes",
                     supportsProperArguments: true
                 },
-                {
-                    exePath: "C:\\Users\\test\\pwsh\\pwsh.exe",
-                    displayName: "pwsh-double-quotes",
-                    supportsProperArguments: true
-                },
             ],
-            filesystem: {},
+            filesystem: {
+                "C:\\Users\\test\\pwsh": {
+                    "pwsh.exe": "",
+                },
+                [path.join(os.homedir(), "pwsh")]: {
+                    "pwsh.exe": "",
+                }
+            },
         }
     ];
 } else {
@@ -693,7 +633,7 @@ if (process.platform === "win32") {
             ],
             filesystem: {
                 "/usr/bin": {
-                    pwsh: "",
+                    "pwsh": "",
                 },
             },
         },
@@ -714,7 +654,7 @@ if (process.platform === "win32") {
             ],
             filesystem: {
                 "/snap/bin": {
-                    pwsh: "",
+                    "pwsh": "",
                 },
             },
         },
@@ -735,7 +675,7 @@ if (process.platform === "win32") {
             ],
             filesystem: {
                 "/usr/local/bin": {
-                    pwsh: "",
+                    "pwsh": "",
                 },
             },
         },
@@ -759,7 +699,7 @@ if (process.platform === "win32") {
             ],
             filesystem: {
                 "/Users/test/.dotnet/tools": {
-                    pwsh: "",
+                    "pwsh": "",
                 },
             },
         },
@@ -783,108 +723,74 @@ if (process.platform === "win32") {
             ],
             filesystem: {
                 "/home/test/.dotnet/tools": {
-                    pwsh: "",
+                    "pwsh": "",
                 },
             },
         },
     ];
 
     additionalPowerShellExes = {
-        "pwsh": "/home/bin/pwsh",
+        "pwsh": "/home/test/bin/pwsh",
         "pwsh-tilde": "~/bin/pwsh",
-        "pwsh-folder": "/home/bin/",
-        "pwsh-folder-no-slash": "/home/bin",
-        "pwsh-single-quotes": "'/home/bin/pwsh'",
-        "pwsh-double-quotes": "\"/home/bin/pwsh\"",
+        "pwsh-folder": "/home/test/bin/",
+        "pwsh-folder-no-slash": "/home/test/bin",
+        "pwsh-single-quotes": "'/home/test/bin/pwsh'",
+        "pwsh-double-quotes": "\"/home/test/bin/pwsh\"",
     };
 
     successAdditionalTestCases = [
-        {   // Also sufficient for macOS as the behavior is the same
+        {
             name: "Linux/macOS (Additional PowerShell Executables)",
             platformDetails: {
                 operatingSystem: platform.OperatingSystem.Linux,
                 isOS64Bit: true,
                 isProcess64Bit: true,
             },
-            environmentVars: {},
-            // Note that for each given path, we expect:
-            // 1. The path as-is.
-            // 2. Any expected permutations of the path (for example, with a tilde or folder expanded).
-            // 3. The path as-is again (in order for a warning to be displayed at the correct time).
-            // An improvement here would be to check the suppressWarning field, but it's not currently exposed.
+            environmentVars: {
+                "USER": "test",
+                "HOME": "/home/test",
+            },
             expectedPowerShellSequence: [
                 {
-                    exePath: "/home/bin/pwsh",
-                    displayName: "pwsh",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/pwsh",
+                    exePath: "/home/test/bin/pwsh",
                     displayName: "pwsh",
                     supportsProperArguments: true
                 },
                 {
+                    // untildify ignores the HOME mock so this is platform-dependent
                     exePath: path.join(os.homedir(), "bin", "pwsh"),
                     displayName: "pwsh-tilde",
                     supportsProperArguments: true
                 },
                 {
-                    exePath: path.join(os.homedir(), "bin", "pwsh"),
-                    displayName: "pwsh-tilde",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/",
+                    exePath: "/home/test/bin/pwsh",
                     displayName: "pwsh-folder",
                     supportsProperArguments: true
                 },
                 {
-                    exePath: "/home/bin/pwsh",
-                    displayName: "pwsh-folder",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/",
-                    displayName: "pwsh-folder",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin",
-                    displayName: "pwsh-folder-no-slash",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/pwsh",
+                    exePath: "/home/test/bin/pwsh",
                     displayName: "pwsh-folder-no-slash",
                     supportsProperArguments: true
                 },
                 {
-                    exePath: "/home/bin",
-                    displayName: "pwsh-folder-no-slash",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/pwsh",
-                    displayName: "pwsh-single-quotes",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/pwsh",
+                    exePath: "/home/test/bin/pwsh",
                     displayName: "pwsh-single-quotes",
                     supportsProperArguments: true
                 },
                 {
-                    exePath: "/home/bin/pwsh",
-                    displayName: "pwsh-double-quotes",
-                    supportsProperArguments: true
-                },
-                {
-                    exePath: "/home/bin/pwsh",
+                    exePath: "/home/test/bin/pwsh",
                     displayName: "pwsh-double-quotes",
                     supportsProperArguments: true
                 },
             ],
-            filesystem: {},
+            filesystem: {
+                "/home/test/bin": {
+                    "pwsh": "",
+                },
+                [path.join(os.homedir(), "bin")]: {
+                    "pwsh": "",
+                }
+            },
         }
     ];
 }
@@ -1099,13 +1005,13 @@ describe("Platform module", function () {
         });
 
         for (const testPlatform of successAdditionalTestCases) {
-            it(`Guesses for ${testPlatform.name}`, function () {
+            it(`Guesses for ${testPlatform.name}`, async function () {
                 setupTestEnvironment(testPlatform);
 
                 const powerShellExeFinder = new platformMock.PowerShellExeFinder(testPlatform.platformDetails, additionalPowerShellExes);
 
                 let i = 0;
-                for (const additionalPwsh of powerShellExeFinder.enumerateAdditionalPowerShellInstallations()) {
+                for await (const additionalPwsh of powerShellExeFinder.enumerateAdditionalPowerShellInstallations()) {
                     const expectedPowerShell = testPlatform.expectedPowerShellSequence[i];
                     i++;