diff --git a/CLIENT_DATA/delsub3264.ins b/CLIENT_DATA/delsub3264.ins
index 93da5a3..c0fdcce 100644
--- a/CLIENT_DATA/delsub3264.ins
+++ b/CLIENT_DATA/delsub3264.ins
@@ -4,10 +4,8 @@
 ; credits: http://www.opsi.org/en/credits/
 
 
-Set $UninstallProgram32$ = $InstallDir32$ + "\" + $UninstallProg32$
 Set $IniFile32$ = $InstallDir32$ + "\opsi-" + $ProductId$ + ".ini"
 
-Set $UninstallProgram64$ = $InstallDir64$ + "\" + $UninstallProg64$
 Set $IniFile64$ = $InstallDir64$ + "\opsi-" + $ProductId$ + ".ini"
 
 if (($INST_SystemType$ = "x86 System") and ($INST_architecture$ = "system specific")) or ($INST_architecture$ = "both") or ($INST_architecture$ = "32 only")
@@ -19,20 +17,19 @@ if (($INST_SystemType$ = "x86 System") and ($INST_architecture$ = "system specif
 	Message "Uninstalling " + $ProductId$ + " "+ $OLD_VERSION$ + "-" + $OLD_CREATOR_TAG$ + $OLD_RELEASE$ + " 32 Bit..."
 
         if FileExists($IniFile32$)
-		Set $UninstallProg32$ = GetValueFromInifile($IniFile32$,"X86","UninstallProg32","XXXXXXXX.exe")
-		Set $UninstallProgramOld32$ = $InstallDir32$ + "\" + $UninstallProg32$
-		if FileExists($UninstallProgramOld32$)
-			comment "Uninstall program found, starting uninstall"
-			Winbatch_uninstall_old_32
-			sub_check_exitcode
-		endif
+                Set $MsiIdOld32$ = GetValueFromInifile($IniFile32$,"X86","MsiId32","{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}")
+                if not (GetRegistryStringValue32("[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\" + $MsiIdOld32$ + "] DisplayName") = "")
+                        comment "Old MSI id " + $MsiIdOld32$ + " found in registry, starting msiexec to uninstall old version"
+                        Winbatch_uninstall_msi_old_32
+                        sub_check_exitcode
+                endif
         endif
-	if FileExists($UninstallProgram32$)
-		comment "Uninstall program found, starting uninstall"
-		Winbatch_uninstall_32
+	if not (GetRegistryStringValue32("[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\" + $MsiId32$ + "] DisplayName") = "")
+		comment "MSI id " + $MsiId32$ + " found in registry, starting msiexec to uninstall"
+		Winbatch_uninstall_msi_32
 		sub_check_exitcode
 	endif
-
+	
 	comment "Delete files"
 	Files_uninstall_32 /32Bit
 	comment "Cleanup registry"
@@ -48,20 +45,19 @@ if ($INST_SystemType$ = "64 Bit System") and (($INST_architecture$ = "system spe
 	Message "Uninstalling " + $ProductId$ + " "+ $OLD_VERSION$ + "-" + $OLD_CREATOR_TAG$ + $OLD_RELEASE$ + " 64 Bit..."
 
         if FileExists($IniFile64$)
-		Set $UninstallProg64$ = GetValueFromInifile($IniFile64$,"X86_64","UninstallProg64","XXXXXXXX.exe")
-		Set $UninstallProgramOld64$ = $InstallDir64$ + "\" + $UninstallProg64$
-		if FileExists($UninstallProgramOld64$)
-			comment "Uninstall program found, starting uninstall"
-			Winbatch_uninstall_old_64
-			sub_check_exitcode
-		endif
+                Set $MsiIdOld64$ = GetValueFromInifile($IniFile64$,"X86_64","MsiId64","{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}")
+                if not (GetRegistryStringValue64("[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\" + $MsiIdOld64$ + "] DisplayName") = "")
+                        comment "Old MSI id " + $MsiIdOld64$ + " found in registry, starting msiexec to uninstall old version"
+                        Winbatch_uninstall_msi_old_64
+                        sub_check_exitcode
+                endif
         endif
-	if FileExists($UninstallProgram64$)
-		comment "Uninstall program found, starting uninstall"
-		Winbatch_uninstall_64
+	if not (GetRegistryStringValue64("[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\" + $MsiId64$ + "] DisplayName") = "")
+		comment "MSI id " + $MsiId64$ + " found in registry, starting msiexec to uninstall"
+		Winbatch_uninstall_msi_64
 		sub_check_exitcode
 	endif
-
+	
 	comment "Delete files"
 	Files_uninstall_64 /64Bit
 	comment "Cleanup registry"
@@ -71,22 +67,22 @@ endif
 comment "Delete program shortcuts"
 LinkFolder_uninstall
 
-[Winbatch_uninstall_old_32]
-"$UninstallProgramOld32$" /SILENT
+[Winbatch_uninstall_msi_old_32]
+msiexec /x $MsiIdOld32$ /qb! REBOOT=ReallySuppress
 
-[Winbatch_uninstall_32]
-"$UninstallProgram32$" /SILENT
+[Winbatch_uninstall_msi_32]
+msiexec /x $MsiId32$ /qb! REBOOT=ReallySuppress
 
 [Files_uninstall_32]
 ; Example for recursively deleting the installation directory (don't forget the trailing backslash):
 ;
 delete -sf "$InstallDir32$\"
 
-[Winbatch_uninstall_old_64]
-"$UninstallProgramOld64$" /SILENT
+[Winbatch_uninstall_msi_old_64]
+msiexec /x $MsiIdOld64$ /qb! REBOOT=ReallySuppress
 
-[Winbatch_uninstall_64]
-"$UninstallProgram64$" /SILENT
+[Winbatch_uninstall_msi_64]
+msiexec /x $MsiId64$ /qb! REBOOT=ReallySuppress
 
 [Files_uninstall_64]
 ; Example for recursively deleting the installation directory:
diff --git a/CLIENT_DATA/setup3264.ins b/CLIENT_DATA/setup3264.ins
index 4b2ca9e..9cf1215 100644
--- a/CLIENT_DATA/setup3264.ins
+++ b/CLIENT_DATA/setup3264.ins
@@ -6,11 +6,9 @@
 [Actions]
 requiredWinstVersion >= "4.11.2.6"
 
-DefVar $UninstallProgram32$
-DefVar $UninstallProgramOld32$
+DefVar $MsiIdOld32$
 DefVar $IniFile32$
-DefVar $UninstallProgram64$
-DefVar $UninstallProgramOld64$
+DefVar $MsiIdOld64$
 DefVar $IniFile64$
 DefVar $IniCfgFile$
 DefVar $LogDir$
@@ -46,7 +44,7 @@ Set $LogDir$ = "%SystemDrive%\tmp"
 ;$ProductId$ should be the name of the product in opsi
 ; therefore please: only lower letters, no umlauts, 
 ; no white space use '-' as a seperator
-Set $MinimumSpace$    = "15 MB"
+Set $MinimumSpace$    = "20 MB"
 ; the path were we find the product after the installation
 Set $InstallDir32$      = "%ProgramFiles32Dir%\PeaZip"
 Set $InstallDir64$      = "%ProgramFiles64Dir%\PeaZip"
@@ -84,7 +82,7 @@ else
 	endif
 
 	if ($INST_SystemType$ = "64 Bit System") and (($INST_architecture$ = "system specific") or ($INST_architecture$ = "both") or ($INST_architecture$ = "64 only"))
-		Message "Installing " + $ProductId$ + " "+ $VERSION$ + "-" + $CREATOR_TAG$ + $RELEASE$ + " 64 Bit..."
+		Message "Installing " + $ProductId$ + " " + $VERSION$ + "-" + $CREATOR_TAG$ + $RELEASE$ + " 64 Bit..."
 		comment "Start setup program"
 		ChangeDirectory "%SCRIPTPATH%"
 		Winbatch_install_64
@@ -100,7 +98,7 @@ else
 endif
 
 [Winbatch_install_32]
-"$Install32Exe$" /SILENT
+msiexec /i "$Instal32Msi$" /l* "$LogDir$\$ProductId$.install_log.txt" /qb! ALLUSERS=1 REBOOT=ReallySuppress
 
 [Files_install_32]
 ; copy the ini file to the InstallDir
@@ -111,7 +109,7 @@ copy "$IniCfgFile$" "$InstallDir32$"
 ; copy -s "%ScriptPath%\files\*.*" "$InstallDir32$"
 
 [Winbatch_install_64]
-"$Install64Exe$" /SILENT
+msiexec /i "$Install64Msi$" /l* "$LogDir$\$ProductId$.install_log.txt" /qb! ALLUSERS=1 REBOOT=ReallySuppress
 
 [Files_install_64]
 ; copy the ini file to the InstallDir
diff --git a/CLIENT_DATA/uninstall3264.ins b/CLIENT_DATA/uninstall3264.ins
index e1adf4a..7a1d96b 100644
--- a/CLIENT_DATA/uninstall3264.ins
+++ b/CLIENT_DATA/uninstall3264.ins
@@ -6,13 +6,9 @@
 [Actions]
 requiredWinstVersion >= "4.11.2.6"
 
-DefVar $UninstallProg32$
-DefVar $UninstallProgram32$
-DefVar $UninstallProgramOld32$
+DefVar $MsiIdOld32$
 DefVar $IniFile32$
-DefVar $UninstallProg64$
-DefVar $UninstallProgram64$
-DefVar $UninstallProgramOld64$
+DefVar $MsiIdOld64$
 DefVar $IniFile64$
 DefVar $IniCfgFile$
 DefVar $LogDir$
diff --git a/builder-product.cfg b/builder-product.cfg
index 9211c81..3ea2c23 100644
--- a/builder-product.cfg
+++ b/builder-product.cfg
@@ -17,23 +17,26 @@ TYPE="public"
 DL_FILE[0]="peazip_2.png"
 DL_SOURCE[0]="http://rocketdock.com/images/screenshots/peazip_2.png"
 
-DL_FILE[1]="peazip-${VERSION}.WINDOWS.exe"
-DL_SOURCE[1]="https://github.com/giorgiotani/PeaZip/releases/download/${VERSION}/peazip-${VERSION}.WINDOWS.exe"
+DL_FILE[1]="peazip-${VERSION}.WINDOWS.msi"
+DL_SOURCE[1]="https://github.com/giorgiotani/PeaZip/releases/download/${VERSION}/peazip-${VERSION}.WINDOWS.msi"
 DL_ARCH[1]="X86"
-DL_WINST_NAME[1]=Install32Exe
+DL_WINST_NAME[1]=Install32Msi
 
-DL_FILE[2]="peazip-${VERSION}.WIN64.exe"
-DL_SOURCE[2]="https://github.com/giorgiotani/PeaZip/releases/download/${VERSION}/peazip-${VERSION}.WIN64.exe"
+DL_FILE[2]="peazip-${VERSION}.WIN64.Msi"
+DL_SOURCE[2]="https://github.com/giorgiotani/PeaZip/releases/download/${VERSION}/peazip-${VERSION}.WIN64.msi"
 DL_ARCH[2]="X86_64"
-DL_WINST_NAME[2]=Install64Exe
+DL_WINST_NAME[2]=Install64Msi
 
 # File array index for the image showing while installing the program
 ICON_DL_INDEX=0
 
 OPSI_INI_SECTION[0]="X86"
-OPSI_INI_OPTION[0]="UninstallProg32"
-OPSI_INI_VALUE[0]="unins000.exe"
+OPSI_INI_OPTION[0]="MsiId32"
+OPSI_INI_VALUE[0]="{9B755822-B264-4E31-933B-9C5E90E4E295}"
+
+# AND
 
 OPSI_INI_SECTION[1]="X86_64"
-OPSI_INI_OPTION[1]="UninstallProg64"
-OPSI_INI_VALUE[1]="unins000.exe"
+OPSI_INI_OPTION[1]="MsiId64"
+OPSI_INI_VALUE[1]="{AFCD9F92-38B4-4EE5-B746-7F7DA8D83D1D}"
+
diff --git a/peazip-6.5.1.WIN64.Msi.sha1sum b/peazip-6.5.1.WIN64.Msi.sha1sum
new file mode 100644
index 0000000..a002259
--- /dev/null
+++ b/peazip-6.5.1.WIN64.Msi.sha1sum
@@ -0,0 +1 @@
+ef0eea96109506256b9d051342ce582811bb3892  /home/mario/.opsi-dist-cache/peazip.peazip-6.5.1/X86_64/peazip-6.5.1.WIN64.Msi
diff --git a/peazip-6.5.1.WIN64.exe.sha1sum b/peazip-6.5.1.WIN64.exe.sha1sum
deleted file mode 100644
index 11aedca..0000000
--- a/peazip-6.5.1.WIN64.exe.sha1sum
+++ /dev/null
@@ -1 +0,0 @@
-94c639cd3f12a3164b549315ba6fb5810bc588ae  /home/mario/.opsi-dist-cache/peazip.peazip-6.5.1/X86_64/peazip-6.5.1.WIN64.exe
diff --git a/peazip-6.5.1.WINDOWS.exe.sha1sum b/peazip-6.5.1.WINDOWS.exe.sha1sum
deleted file mode 100644
index dc3e6fb..0000000
--- a/peazip-6.5.1.WINDOWS.exe.sha1sum
+++ /dev/null
@@ -1 +0,0 @@
-871cf60f8fc8d1f3dfc48390b2f0ec90bc89a821  /home/mario/.opsi-dist-cache/peazip.peazip-6.5.1/X86/peazip-6.5.1.WINDOWS.exe
diff --git a/peazip-6.5.1.WINDOWS.msi.sha1sum b/peazip-6.5.1.WINDOWS.msi.sha1sum
new file mode 100644
index 0000000..5ddf983
--- /dev/null
+++ b/peazip-6.5.1.WINDOWS.msi.sha1sum
@@ -0,0 +1 @@
+964e2f189318354cbf975f67c63f442368a16741  /home/mario/.opsi-dist-cache/peazip.peazip-6.5.1/X86/peazip-6.5.1.WINDOWS.msi