diff --git a/README.md b/README.md
index c4ec9a7..eb83e19 100644
--- a/README.md
+++ b/README.md
@@ -26,13 +26,21 @@ a result. The "thin" varieties have the CPython 3.12 distribution gouged out and
 result. In its place a [`ptex`](https://github.com/a-scie/ptex) binary is included that fills in the
 CPython 3.12 distribution by fetching it when the "thin" `science` binary is first run.
 
-You can install the latest `science` release using the `install.sh` script like so:
-
-```
-$ curl --proto '=https' --tlsv1.2 -LSsf https://raw.githubusercontent.com/a-scie/lift/main/install.sh | bash
-...
-$ science -V
-```
+You can install the latest `science` "fat" binary release using a convenience install script
+like so:
+
++ Linux and macOS:
+    ```
+    $ curl --proto '=https' --tlsv1.2 -LSsf https://raw.githubusercontent.com/a-scie/lift/main/install.sh | bash
+    ...
+    $ science -V
+    ```
++ Windows PowerShell:
+    ```
+    > irm https://raw.githubusercontent.com/a-scie/lift/main/install.ps1 | iex
+    ...
+    > science -V
+    ```
 
 The high level documentation is currently thin! The command line help is pretty decent though; so
 try there 1st starting with just running `science` with no arguments.
diff --git a/install.ps1 b/install.ps1
new file mode 100644
index 0000000..7fb1626
--- /dev/null
+++ b/install.ps1
@@ -0,0 +1,172 @@
+#!/usr/bin/env pwsh
+# Copyright 2024 Science project contributors.
+# Licensed under the Apache License, Version 2.0 (see LICENSE).
+
+<#
+.SYNOPSIS
+  Installs the `science.exe` executable.
+
+.DESCRIPTION
+  Downloads and installs the latest version of the science executable by default.
+  The download is first verified against the published checksum before being installed.
+  The install process will add the science executable to your user PATH environment variable
+  if needed as well as to the current shell session PATH for immediate use.
+
+.PARAMETER Help
+  Display this help message.
+
+.PARAMETER BinDir
+  The directory to install the science binary in.
+
+.PARAMETER NoModifyPath
+  Do not automatically add -BinDir to the PATH.
+
+.PARAMETER Version
+  The version of the science binary to install, the latest version by default.
+  The available versions can be seen at:
+    https://github.com/a-scie/lift/releases
+
+.INPUTS
+  None
+
+.OUTPUTS
+  The path of the installed science executable.
+
+.LINK
+  Docs https://science.scie.app
+
+.LINK
+  Chat https://scie.app/discord
+
+.LINK
+  Source https://github.com/a-scie/lift
+#>
+
+param (
+  [Alias("h")]
+  [switch]$Help,
+
+  [Alias("d")]
+  [string]$BinDir = (
+    # N.B.: PowerShell>=6 supports varargs, but to retain compatibility with older PowerShell, we
+    # just Join-Path twice.
+    # See: https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/join-path?view=powershell-7.4#-additionalchildpath
+    Join-Path (
+      Join-Path ([Environment]::GetFolderPath("LocalApplicationData")) "Programs") "Science"
+  ),
+
+  [switch]$NoModifyPath,
+
+  [Alias("V")]
+  [string]$Version = "latest/download"
+)
+
+$ErrorActionPreference = 'Stop'
+
+function Green {
+  [Parameter(Position=0)]
+  param ($Message)
+
+  Write-Host $Message -ForegroundColor Green
+}
+
+function Warn {
+  [Parameter(Position=0)]
+  param ($Message)
+
+  Write-Host $Message -ForegroundColor Yellow
+}
+
+function Die {
+  [Parameter(Position=0)]
+  param ($Message)
+
+  Write-Host $Message -ForegroundColor Red
+  exit 1
+}
+
+function TemporaryDirectory {
+  $Tmp = [System.IO.Path]::GetTempPath()
+  $Unique = (New-Guid).ToString("N")
+  $TempDir = New-Item -ItemType Directory -Path (Join-Path $Tmp "$Unique")
+  trap {
+    Remove-Item $TempDir -Recurse
+  }
+  return $TempDir
+}
+
+function Fetch {
+  param (
+    [string]$Url,
+    [string]$DestFile
+  )
+
+  Invoke-RestMethod -Uri $Url -OutFile $DestFile
+}
+
+function InstallFromUrl {
+  param (
+    [string]$Url,
+    $DestDir
+  )
+
+  $Sha256Url = "$Url.sha256"
+
+  $Workdir = TemporaryDirectory
+  $ScienceExeFile = "$Workdir\science.exe"
+  $Sha256File = "$Workdir\science.exe.sha256"
+
+  Fetch -Url $Url -DestFile $ScienceExeFile
+  Fetch -Url $Sha256Url -DestFile $Sha256File
+  Green "Download completed successfully"
+
+  $ExpectedHash = ((Get-Content $Sha256File).Trim().ToLower() -Split '\s+',2)[0]
+  $ActualHash = (Get-FileHash $ScienceExeFile -Algorithm SHA256).Hash.ToLower()
+  if ($ActualHash -eq $ExpectedHash) {
+    Green "Download matched it's expected sha256 fingerprint, proceeding"
+  } else {
+    Die "Download from $Url did not match the fingerprint at $Sha256Url"
+  }
+
+  if (!(Test-Path $BinDir)) {
+    New-Item $DestDir -ItemType Directory | Out-Null
+  }
+  Move-Item $ScienceExeFile $DestDir -Force
+}
+
+if ($Help) {
+  Get-Help -Detailed $PSCommandPath
+  exit 0
+}
+
+$Version = switch ($Version) {
+  'latest/download' { 'latest/download' }
+  default { "download/v$Version" }
+}
+
+$Arch = switch -Wildcard ((Get-CimInstance Win32_operatingsystem).OSArchitecture) {
+  'arm*' { 'aarch64' }
+  default { 'x86_64' }
+}
+
+$DownloadURL = "https://github.com/a-scie/lift/releases/$Version/science-fat-windows-$Arch.exe"
+
+Green "Download URL is: $DownloadURL"
+InstallFromUrl -Url $DownloadURL -DestDir $BinDir
+
+if (!(";$Path;".ToLower() -like "*;$BinDir;*".ToLower())) {
+  if ($NoModifyPath) {
+    Warn "WARNING: $BinDir is not detected on `$PATH"
+    Warn (
+      "You'll either need to invoke $BinDir\science.exe explicitly or else add $BinDir to your " +
+      "PATH."
+    )
+  } else {
+    $User = [System.EnvironmentVariableTarget]::User
+    $Path = [System.Environment]::GetEnvironmentVariable('Path', $User)
+    if (!(";$Path;".ToLower() -like "*;$BinDir;*".ToLower())) {
+      [System.Environment]::SetEnvironmentVariable('Path', "$Path;$BinDir", $User)
+      $Env:Path += ";$BinDir"
+    }
+  }
+}
diff --git a/install.sh b/install.sh
index 6f7346d..cdea844 100755
--- a/install.sh
+++ b/install.sh
@@ -39,7 +39,8 @@ function gc() {
   if (($# > 0)); then
     _GC+=("$@")
   else
-    # Check if $_GC has members to avoid "unbound variable" warnings if gc w/ arguments is never called.
+    # Check if $_GC has members to avoid "unbound variable" warnings if gc w/ arguments is never
+    # called.
     if ! [ ${#_GC[@]} -eq 0 ]; then
       rm -rf "${_GC[@]}"
     fi
@@ -76,7 +77,7 @@ function determine_arch() {
     amd64*)    echo "x86_64" ;;
     arm64*)    echo "aarch64" ;;
     aarch64*)  echo "aarch64" ;;
-    *)        die "unknown arch: ${read_arch}" ;;
+    *)         die "unknown arch: ${read_arch}" ;;
   esac
 }
 
@@ -89,7 +90,8 @@ function fetch() {
   local dest
   dest="${dest_dir}/$(basename "${url}")"
 
-  # N.B. Curl is included on Windows 10+: https://devblogs.microsoft.com/commandline/tar-and-curl-come-to-windows/
+  # N.B. Curl is included on Windows 10+:
+  #   https://devblogs.microsoft.com/commandline/tar-and-curl-come-to-windows/
   curl --proto '=https' --tlsv1.2 -SfL --progress-bar -o "${dest}" "${url}"
 }
 
@@ -154,9 +156,6 @@ Installs the \`science\` binary.
 -d | --bin-dir:
   The directory to install the science binary in, "~/.local/bin" by default.
 
--b | --base-name:
-  The name to use for the science binary, "science" by default.
-
 -V | --version:
   The version of the science binary to install, the latest version by default.
   The available versions can be seen at:
@@ -166,7 +165,6 @@ __EOF__
 }
 
 INSTALL_PREFIX="${HOME}/.local/bin"
-INSTALL_FILE="science"
 VERSION="latest/download"
 
 # Parse arguments.
@@ -180,10 +178,6 @@ while (($# > 0)); do
       INSTALL_PREFIX="$2"
       shift
       ;;
-    --base-name | -b)
-      INSTALL_FILE="$2"
-      shift
-      ;;
     --version | -V)
       VERSION="download/v${2}"
       shift
@@ -198,9 +192,10 @@ done
 
 ARCH="$(determine_arch)"
 DIRSEP=$([[ "${OS}" == "windows" ]] && echo "\\" || echo "/")
-INSTALL_DEST="${INSTALL_PREFIX}${DIRSEP}${INSTALL_FILE}"
-DL_EXT=$([[ "${OS}" == "windows" ]] && echo ".exe" || echo "")
-DL_URL="https://github.com/a-scie/lift/releases/${VERSION}/science-fat-${OS}-${ARCH}${DL_EXT}"
+EXE_EXT=$([[ "${OS}" == "windows" ]] && echo ".exe" || echo "")
+
+INSTALL_DEST="${INSTALL_PREFIX}${DIRSEP}science${EXE_EXT}"
+DL_URL="https://github.com/a-scie/lift/releases/${VERSION}/science-fat-${OS}-${ARCH}${EXE_EXT}"
 
 green "Download URL is: ${DL_URL}"
 install_from_url "${DL_URL}" "${INSTALL_DEST}"
@@ -208,5 +203,6 @@ install_from_url "${DL_URL}" "${INSTALL_DEST}"
 # Warn if the install prefix is not on $PATH.
 if ! [[ ":$PATH:" == *":${INSTALL_PREFIX}:"* ]]; then
   warn "WARNING: ${INSTALL_PREFIX} is not detected on \$PATH"
-  warn "You'll either need to invoke ${INSTALL_DEST} explicitly or else add ${INSTALL_PREFIX} to your shell's PATH."
+  warn "You'll either need to invoke ${INSTALL_DEST} explicitly or else add ${INSTALL_PREFIX} \
+to your shell's PATH."
 fi
diff --git a/tests/test_installer.py b/tests/test_installer.py
index be14058..8f9eef1 100644
--- a/tests/test_installer.py
+++ b/tests/test_installer.py
@@ -1,9 +1,8 @@
 # Copyright 2024 Science project contributors.
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
-import shutil
 import subprocess
-from pathlib import Path, PurePath
+from pathlib import Path
 
 import pytest
 from _pytest.tmpdir import TempPathFactory
@@ -13,29 +12,10 @@
 
 @pytest.fixture(scope="module")
 def installer(build_root: Path) -> list:
-    installer = build_root / "install.sh"
     if IS_WINDOWS:
-        # TODO(John Sirois): Get rid of all this shenanigans and write an install.ps1 instead:
-        #  https://github.com/a-scie/lift/issues/91
-
-        # Given a git for Windows install at C:\Program Files\Git, we will find the git executable
-        # at one of these two locations:
-        # + Running under cmd or pwsh, etc.: C:\Program Files\Git\cmd\git.EXE
-        # + Running under git bash:          C:\Program Files\Git\mingw64\bin\git.EXE
-        # We expect the msys2 root to be at the git for Windows install root, which is
-        # C:\Program Files\Git in this case.
-        assert (git := shutil.which("git")) is not None, "This test requires Git bash on Windows."
-        msys2_root = PurePath(git).parent.parent
-        if "mingw64" == msys2_root.name:
-            msys2_root = msys2_root.parent
-
-        assert (bash := shutil.which("bash", path=msys2_root / "usr" / "bin")) is not None, (
-            f"The git executable at {git} does not appear to have msys2 root at the expected path "
-            f"of {msys2_root}."
-        )
-        return [bash, installer]
+        return ["pwsh", build_root / "install.ps1", "-NoModifyPath"]
     else:
-        return [installer]
+        return [build_root / "install.sh"]
 
 
 def run_captured(cmd: list):
@@ -43,10 +23,11 @@ def run_captured(cmd: list):
 
 
 def test_installer_help(installer: list):
-    """Validates -h|--help in the installer."""
-    for tested_flag in ("-h", "--help"):
+    """Validates help in the installer."""
+    long_help = "-Help" if IS_WINDOWS else "--help"
+    for tested_flag in ("-h", long_help):
         assert (result := run_captured(installer + [tested_flag])).returncode == 0
-        assert "--help" in result.stdout, "Expected '--help' in tool output"
+        assert long_help in result.stdout, f"Expected '{long_help}' in tool output"
 
 
 def test_installer_fetch_latest(tmp_path_factory: TempPathFactory, installer: list):
@@ -55,7 +36,9 @@ def test_installer_fetch_latest(tmp_path_factory: TempPathFactory, installer: li
     bin_dir = test_dir / "bin"
 
     assert (result := run_captured(installer + ["-d", bin_dir])).returncode == 0
-    assert "success" in result.stderr, "Expected 'success' in tool stderr logging"
+    assert (
+        "success" in result.stdout if IS_WINDOWS else result.stderr
+    ), "Expected 'success' in tool stderr logging"
 
     assert (result := run_captured([bin_dir / "science", "-V"])).returncode == 0
     assert result.stdout.strip(), "Expected version output in tool stdout"
@@ -66,18 +49,16 @@ def test_installer_fetch_argtest(tmp_path_factory: TempPathFactory, installer: l
     test_dir = tmp_path_factory.mktemp("install-test")
     test_ver = "0.7.0"
     bin_dir = test_dir / "bin"
-    bin_file = f"science{test_ver}"
 
-    assert (
-        result := run_captured(installer + ["-V", test_ver, "-b", bin_file, "-d", bin_dir])
-    ).returncode == 0
-    assert "success" in result.stderr, "Expected 'success' in tool stderr logging"
+    assert (result := run_captured(installer + ["-V", test_ver, "-d", bin_dir])).returncode == 0
+    output = result.stdout if IS_WINDOWS else result.stderr
+    assert "success" in output, "Expected 'success' in tool stderr logging"
 
     # Ensure missing $PATH entry warning (assumes our temp dir by nature is not on $PATH).
-    assert "is not detected on $PATH" in result.stderr, "Expected missing $PATH entry warning"
+    assert "is not detected on $PATH" in output, "Expected missing $PATH entry warning"
 
     # Check expected versioned binary exists.
-    assert (result := run_captured([bin_dir / bin_file, "-V"])).returncode == 0
+    assert (result := run_captured([bin_dir / "science", "-V"])).returncode == 0
     assert (
         result.stdout.strip() == test_ver
     ), f"Expected version output in tool stdout to be {test_ver}"