diff --git a/install.bat b/install.bat
index af9ca9e..37c3c3d 100644
--- a/install.bat
+++ b/install.bat
@@ -59,13 +59,25 @@ echo This is a one-time setup (~100 MB). Please wait.
 echo.
 
 :: --- Method 1: winget (cleanest; available on Win10 1709+ and all Win11) ---
+:: --scope user is critical: without it winget defaults to a machine-wide
+:: install (lands in %ProgramData%) which REQUIRES admin. A normal double-click
+:: (no elevation) then fails silently and conda never installs. --scope user
+:: installs to %USERPROFILE%\miniforge3 with no admin needed — which is also one
+:: of the locations :rescan_conda searches.
 winget --version >nul 2>&1
 if %errorlevel% equ 0 (
     echo Installing via winget...
-    winget install --id CondaForge.Miniforge3 --exact --silent ^
+    winget install --id CondaForge.Miniforge3 --exact --silent --scope user ^
         --accept-package-agreements --accept-source-agreements
-    if !errorlevel! equ 0 goto :rescan_conda
-    echo winget install failed — falling back to direct download.
+    :: winget returns non-zero when the package is already installed, so don't
+    :: trust the exit code — rescan for conda and only fall through to the
+    :: direct download if it's genuinely still missing.
+    for %%C in (
+        "%LOCALAPPDATA%\miniforge3\Scripts\conda.exe"
+        "%USERPROFILE%\miniforge3\Scripts\conda.exe"
+        "%ProgramData%\miniforge3\Scripts\conda.exe"
+    ) do if exist %%C goto :rescan_conda
+    echo winget did not produce a usable conda — falling back to direct download.
     echo.
 )
 
@@ -78,6 +90,7 @@ if %errorlevel% equ 0 (
 set "MF_INSTALLER=%TEMP%\Miniforge3-installer.exe"
 set "MF_URL=https://github.com/conda-forge/miniforge/releases/latest/download/Miniforge3-Windows-x86_64.exe"
 
+del /q "%MF_INSTALLER%" >nul 2>&1
 echo Downloading Miniforge3...
 curl -Lk --progress-bar "%MF_URL%" -o "%MF_INSTALLER%" 2>&1
 if %errorlevel% neq 0 (
@@ -95,6 +108,23 @@ if not exist "%MF_INSTALLER%" (
     exit /b 1
 )
 
+:: Verify the download is a real installer, not a truncated file or an HTML
+:: error page served with a 200. The Miniforge installer is ~78 MB; anything
+:: under 40 MB means the download failed even though a file exists.
+for %%A in ("%MF_INSTALLER%") do set "MF_SIZE=%%~zA"
+if not defined MF_SIZE set "MF_SIZE=0"
+if %MF_SIZE% LSS 41943040 (
+    echo.
+    echo ERROR: Downloaded Miniforge3 installer is only %MF_SIZE% bytes — the
+    echo download was incomplete or blocked. Check your internet/proxy, or install
+    echo manually then re-run install.bat:
+    echo   https://github.com/conda-forge/miniforge/releases/latest
+    echo.
+    del /q "%MF_INSTALLER%" >nul 2>&1
+    pause
+    exit /b 1
+)
+
 echo Installing Miniforge3 (this takes ~1 minute)...
 start /wait "" "%MF_INSTALLER%" /S /InstallationType=JustMe /AddToPath=0 /RegisterPython=0 /NoShortcuts=1 /NoRegistry=1
 if %errorlevel% neq 0 (