diff --git a/docs/release.md b/docs/release.md
index c4d5f337..06a2c3b1 100644
--- a/docs/release.md
+++ b/docs/release.md
@@ -257,8 +257,9 @@ For a pinned version or custom user-writable directory:
 
 The installer verifies the published `.zip.sha256` before extraction, installs
 both `wright.exe` and `wright-lsp.exe`, and runs both binaries directly for a
-version smoke check. If the install directory is not already on the user
-`PATH`, it prints a copyable PowerShell command and asks you to open a new
+version smoke check. If the default install directory is not already on the
+user `PATH`, it adds it and updates the current session; with a custom
+`-InstallDir` it prints a copyable PowerShell command and asks you to open a new
 terminal. It does not require Cargo, npm, or a source checkout.
 
 ### Release smoke test
@@ -336,8 +337,9 @@ by `scripts/test-install.sh` against a mock R2 route on Linux and macOS CI.
 stable release by default or an exact `-Version`, downloads the canonical ZIP
 and matching `.sha256`, verifies the checksum before extraction, installs both
 executables into the user-writable default directory or `-InstallDir`, and
-runs a direct native version smoke check. When needed, it prints an actionable
-user `PATH` update instruction. Its functional behavior is covered by
+runs a direct native version smoke check. When needed, it adds the default
+directory to the user `PATH`, or prints an actionable update instruction for a
+custom `-InstallDir`. Its functional behavior is covered by
 `scripts/test-install.ps1` against a local test release server on Windows.
 
 
diff --git a/install.ps1 b/install.ps1
index 9e5ce114..de48a23c 100644
--- a/install.ps1
+++ b/install.ps1
@@ -102,7 +102,8 @@ if ($OsArchitecture -ne "AMD64") {
 
 $BaseUrl = Resolve-Setting $BaseUrl "WRIGHT_INSTALL_BASE_URL" "https://install.wrightkit.dev/wright"
 $Version = Get-Version $Version $BaseUrl
-if (-not $InstallDir) {
+$DefaultInstallDir = -not $InstallDir
+if ($DefaultInstallDir) {
     $InstallRoot = if ($env:LOCALAPPDATA) { $env:LOCALAPPDATA } else { $env:USERPROFILE }
     if (-not $InstallRoot) { Fail "could not determine a user-writable install directory; pass -InstallDir" }
     $InstallDir = Join-Path $InstallRoot "Programs\Wright\bin"
@@ -175,10 +176,17 @@ try {
         $_.Trim().TrimEnd("\") -ieq $PathEntry
     }).Count -gt 0
     if (-not $PathContainsInstallDir) {
-        $DisplayPath = $InstallDir.Replace("'", "''")
-        Write-Host "note: '$InstallDir' is not on your user PATH; add it and open a new terminal to use wright by name:"
-        Write-Host "  `$userPath = [Environment]::GetEnvironmentVariable('Path', 'User')"
-        Write-Host "  [Environment]::SetEnvironmentVariable('Path', (`$userPath.TrimEnd(';') + ';$DisplayPath'), 'User')"
+        if ($DefaultInstallDir) {
+            $NewUserPath = (@($PathEntries | Where-Object { $_.Trim() }) + $PathEntry) -join ";"
+            [Environment]::SetEnvironmentVariable("Path", $NewUserPath, "User")
+            $env:Path = "$env:Path;$PathEntry"
+            Write-Host "==> added '$PathEntry' to your user PATH; terminals opened from now on can run wright"
+        } else {
+            $DisplayPath = $InstallDir.Replace("'", "''")
+            Write-Host "note: '$InstallDir' is not on your user PATH; add it and open a new terminal to use wright by name:"
+            Write-Host "  `$userPath = [Environment]::GetEnvironmentVariable('Path', 'User')"
+            Write-Host "  [Environment]::SetEnvironmentVariable('Path', (`$userPath.TrimEnd(';') + ';$DisplayPath'), 'User')"
+        }
     }
     Write-Host "==> done: wright and wright-lsp $Version installed in $InstallDir"
 } finally {