diff --git a/.github/workflows/build-conda-installer.yml b/.github/workflows/build-conda-installer.yml
index 7acde4e..df70e49 100644
--- a/.github/workflows/build-conda-installer.yml
+++ b/.github/workflows/build-conda-installer.yml
@@ -5,6 +5,7 @@ on:
   workflow_dispatch:
   push:
       branches:
+        - "micromamba-installer"
         - 'master'
         - 'releases/**'
         - 'testing/**'
@@ -31,7 +32,7 @@ jobs:
       matrix:
         include:
           - python-version: "3.9.12"
-            miniconda-version: "py39_4.12.0"
+            micromamba-version: "1.5.1-0"
 
     defaults:
       run:
@@ -90,15 +91,17 @@ jobs:
                          pyqt=5.15.* \
                          pyqtwebengine=5.15.* \
                          Orange3=$VERSION \
-                         blas=*=openblas
+                         blas=*=openblas \
+                         mamba
             conda list -p ./env --export --explicit --md5 > env-spec.txt
+            cat env-spec.txt
             echo "CONDA_SPEC_FILE=env-spec.txt" >> $GITHUB_ENV
           fi
 
       - name: Build installer
         env:
           PLATTAG: win_amd64
-          MINICONDA_VERSION: ${{ matrix.miniconda-version }}
+          MICROMAMBA_VERSION: ${{ matrix.micromamba-version }}
         run: |
           mkdir dist
           export PATH="$(cygpath -u 'C:\Program Files (x86)\NSIS'):$PATH"
@@ -107,7 +110,7 @@ jobs:
               --platform $PLATTAG \
               --cache-dir .cache \
               --dist-dir dist \
-              --miniconda-version "$MINICONDA_VERSION" \
+              --micromamba-version "$MICROMAMBA_VERSION" \
               --env-spec "$CONDA_SPEC_FILE" \
               --online no
 
diff --git a/scripts/windows/micromambainstall.bat b/scripts/windows/micromambainstall.bat
index b7411ad..de11d6b 100644
--- a/scripts/windows/micromambainstall.bat
+++ b/scripts/windows/micromambainstall.bat
@@ -8,24 +8,15 @@ rem Path to micromamba executable
 set MICROMAMBA=%~2
 set MAMBA_ROOT_PREFIX=%~3
 
-rem mamba has problems installing from "local" files? Make pkgs available in
-rem pkg cache
-rem mkdir "%PREFIX%\pkgs"
-rem copy *.conda *.bz2 "%PREFIX%\pkgs"
-rem !!! ~FIX THIS: !!! root prefix cannot be the same as install prefix ??!!!
-rem !!! FIX THIS:Non-conda folder exists at prefix ?? !!!
-
 if not exist "%PREFIX%\conda-meta" (
     echo Creating a conda env in "%PREFIX%"
     mkdir "%PREFIX%\conda-meta"
-    rem # Create an empty initial skeleton to layout the conda, activate.bat
-    rem # and other things needed to manage the environment.
-    call "%MICROMAMBA%" create --yes --root-prefix "%MAMBA_ROOT_PREFIX%" --prefix "%PREFIX%" --file .\conda-spec.txt ^
-        || exit /b !ERRORLEVEL!
-) else (
-    call "%MICROMAMBA%" install --yes --root-prefix "%MAMBA_ROOT_PREFIX%" --prefix "%PREFIX%" --file .\conda-spec.txt ^
-        || exit /b !ERRORLEVEL!
 )
+if not exist "%PREFIX%\pkgs" (
+    mkdir "%PREFIX%\pkgs"
+)
+call "%MICROMAMBA%" install --yes --root-prefix "%MAMBA_ROOT_PREFIX%" --prefix "%PREFIX%" --file .\conda-spec.txt ^
+        || exit /b !ERRORLEVEL!
 
 call "%MICROMAMBA%" install --yes --root-prefix "%MAMBA_ROOT_PREFIX%" --prefix "%PREFIX%" mamba
 
@@ -44,13 +35,13 @@ set "CONDA_BAT=%PREFIX%\Scripts\conda.bat"
 echo @echo off>                    "%CONDA_BAT%"
 echo call "%PREFIX%\condabin\mamba" --prefix "%PREFIX%" %%*>>          "%CONDA_BAT%"
 
-%MICROMAMBA% --root-prefix %MAMBA_ROOT_PREFIX% shell hook -s cmd.exe
+:: %MICROMAMBA% --root-prefix %MAMBA_ROOT_PREFIX% shell hook -s cmd.exe
 
-set "ACTIVATE_BAT=%PREFIX%\Scripts\activate.bat"
-if not exist "%ACTIVATE_BAT%" (
-    echo @echo off >  "%ACTIVATE_BAT%"
-    echo call "%MAMBA_ROOT_PREFIX%\condabin\activate.bat" "%PREFIX%" >> "%ACTIVATE_BAT%"
-)
+::set "ACTIVATE_BAT=%PREFIX%\Scripts\activate.bat"
+::if not exist "%ACTIVATE_BAT%" (
+::    echo @echo off >  "%ACTIVATE_BAT%"
+::    echo call "%MAMBA_ROOT_PREFIX%\condabin\activate.bat" "%PREFIX%" >> "%ACTIVATE_BAT%"
+::)
 
 rem # install custom sitecustomize module
 copy sitecustomize.py "%PREFIX%\Lib\