diff --git a/icons/make-msw-ico.sh b/icons/make-msw-ico.sh
index 7445b06..9c1a2f5 100755
--- a/icons/make-msw-ico.sh
+++ b/icons/make-msw-ico.sh
@@ -5,3 +5,7 @@ SIZES=`cat sizes`
 PNGS=`for A in $SIZES; do echo $[A]x$[A]/tg-timer.png; done`
 
 icotool -c -o tg-timer.ico $PNGS
+
+PNGS=`for A in $SIZES; do echo $[A]x$[A]/tg-document.png; done`
+
+icotool -c -o tg-document.ico $PNGS
diff --git a/icons/tg-document.ico b/icons/tg-document.ico
new file mode 100644
index 0000000..92775d8
Binary files /dev/null and b/icons/tg-document.ico differ
diff --git a/icons/tg-timer.ico b/icons/tg-timer.ico
index 903875b..6a13c7f 100644
Binary files a/icons/tg-timer.ico and b/icons/tg-timer.ico differ
diff --git a/packaging/make_msi.sh b/packaging/make_msi.sh
index 401b327..600ad67 100755
--- a/packaging/make_msi.sh
+++ b/packaging/make_msi.sh
@@ -12,6 +12,7 @@ ABSDIR=`cd "$DIR"; pwd`
 RESOURCES=`cd "$1"; pwd`
 
 TARGET="$ABSDIR/../build/msi"
+TMP="$ABSDIR/../build/tmp"
 
 cd "$ABSDIR"/..
 
@@ -20,14 +21,17 @@ VERSION=`cat version`
 make
 
 rm -rf "$TARGET"
+rm -rf "$TMP"
 mkdir -p "$TARGET"
 cp "$ABSDIR/tg-timer.wxs" "$TARGET"
 cp "$ABSDIR/LICENSE.rtf" "$TARGET"
 cp "$ABSDIR/../README.md" "$TARGET"
 cp "$ABSDIR/../LICENSE" "$TARGET"
 cp "$ABSDIR/../build/tg.exe" "$TARGET"
-cp -r "$RESOURCES"/* "$TARGET"
-heat dir "$RESOURCES" -srd -gg -sreg -dr INSTALLDIR -cg Resources -out "$TARGET/Resources.wxs"
+cp -r "$RESOURCES" "$TMP"
+cp "$ABSDIR/../icons/tg-document.ico" "$TMP"
+heat dir "$TMP" -srd -gg -sreg -dr INSTALLDIR -cg Resources -out "$TARGET/Resources.wxs"
+mv "$TMP"/* "$TARGET"
 
 cd "$TARGET"
 
diff --git a/packaging/tg-timer.wxs b/packaging/tg-timer.wxs
index 6a764d9..23f0e30 100644
--- a/packaging/tg-timer.wxs
+++ b/packaging/tg-timer.wxs
@@ -1,6 +1,6 @@
 <?xml version='1.0' encoding='windows-1252'?>
 <Wix xmlns='http://schemas.microsoft.com/wix/2006/wi'>
-  <Product Name='Tg' Id='3751b37e-963f-40dd-bb9c-a854f7e52d40' UpgradeCode='088fdac7-fc91-4881-a2db-eed04425a207'
+  <Product Name='Tg' Id='e679153b-2568-496a-8c08-a85631d2f583' UpgradeCode='088fdac7-fc91-4881-a2db-eed04425a207'
     Language='1033' Codepage='1252' Version='0.4.1' Manufacturer='Marcello Mamino'>
 
     <Package Id='*' Keywords='Installer'
@@ -17,18 +17,23 @@
       <Directory Id='ProgramFilesFolder' Name='PFiles'>
         <Directory Id='INSTALLDIR' Name='tg-timer'>
 
-          <Component Id='MainExecutable' Guid='fa6272ec-38c4-4efc-b804-36f44496fae8'>
+          <Component Id='MainExecutable' Guid='0853715e-cb1f-4e3d-809e-4ba4797ad06a'>
             <File Id='TgEXE' Name='tg.exe' DiskId='1' Source='tg.exe' KeyPath='yes'>
               <Shortcut Id='startmenuTg' Directory='ProgramMenuDir' Name='Tg 0.4.1-test' WorkingDirectory='INSTALLDIR' Icon='tg.exe' IconIndex='0' Advertise='yes' />
               <Shortcut Id='desktopTg' Directory='DesktopFolder' Name='Tg 0.4.1-test' WorkingDirectory='INSTALLDIR' Icon='tg.exe' IconIndex='0' Advertise='yes' />
             </File>
+            <ProgId Id='TgjFile' Description='Tg data file' Icon='tg-document.ico'>
+              <Extension Id='tgj' ContentType='application/x-tg-timer-data'>
+                <Verb Id='open' Command='Open' TargetFile='TgEXE' Argument='"%1"' />
+              </Extension>
+            </ProgId>
           </Component>
 
-          <Component Id='License' Guid='bed22c82-e553-4b69-abe1-61a9f2577795'>
+          <Component Id='License' Guid='2b307b4e-14c2-4097-bfeb-a2c5836eb6e5'>
             <File Id='License' Name='LICENSE' DiskId='1' Source='LICENSE' KeyPath='yes' />
           </Component>
 
-          <Component Id='Readme' Guid='a53f04c5-b051-4e9d-b98a-25f6110a1d3d'>
+          <Component Id='Readme' Guid='1ba234c1-dce4-47ef-b100-83261f8e0f79'>
             <File Id='Readme' Name='README.md' DiskId='1' Source='README.md' KeyPath='yes' />
           </Component>
 
@@ -37,7 +42,7 @@
 
       <Directory Id='ProgramMenuFolder' Name='Programs'>
         <Directory Id='ProgramMenuDir' Name='Tg 0.4.1-test'>
-          <Component Id='ProgramMenuDir' Guid='b9d30e65-210f-4dbc-92e7-e2fec8ab470b'>
+          <Component Id='ProgramMenuDir' Guid='29e56065-c1ad-4bb2-9ab5-b45c989ca7d7'>
             <RemoveFolder Id='ProgramMenuDir' On='uninstall' />
             <RegistryValue Root='HKCU' Key='Software\[Manufacturer]\[ProductName]' Type='string' Value='' KeyPath='yes' />
           </Component>
diff --git a/packaging/tg-timer.wxs.template b/packaging/tg-timer.wxs.template
index 6ba0f51..ab3580e 100644
--- a/packaging/tg-timer.wxs.template
+++ b/packaging/tg-timer.wxs.template
@@ -22,6 +22,11 @@
               <Shortcut Id='startmenuTg' Directory='ProgramMenuDir' Name='Tg #VERSION#' WorkingDirectory='INSTALLDIR' Icon='tg.exe' IconIndex='0' Advertise='yes' />
               <Shortcut Id='desktopTg' Directory='DesktopFolder' Name='Tg #VERSION#' WorkingDirectory='INSTALLDIR' Icon='tg.exe' IconIndex='0' Advertise='yes' />
             </File>
+            <ProgId Id='TgjFile' Description='Tg data file' Icon='tg-document.ico'>
+              <Extension Id='tgj' ContentType='application/x-tg-timer-data'>
+                <Verb Id='open' Command='Open' TargetFile='TgEXE' Argument='"%1"' />
+              </Extension>
+            </ProgId>
           </Component>
 
           <Component Id='License' Guid='#UUID#'>