diff --git a/build/windows/install.nsi b/build/windows/install.nsi
index 90597dca..fa2ed2a3 100644
--- a/build/windows/install.nsi
+++ b/build/windows/install.nsi
@@ -10,20 +10,20 @@
 !define MAIN_APP_EXE "backrest-windows-tray.exe"
 !define INSTALL_TYPE "SetShellVarContext current"
 !define REG_ROOT "HKCU"
-!define REG_APP_PATH "Software\Microsoft\Windows\CurrentVersion\App Paths\${MAIN_APP_EXE}"
-!define UNINSTALL_PATH "Software\Microsoft\Windows\CurrentVersion\Uninstall\${APP_NAME}"
-
+!define REG_UNINSTALL_PATH "Software\Microsoft\Windows\CurrentVersion\Uninstall\${APP_NAME}"
 !define REG_START_MENU "Start Menu Folder"
-
 # Extract version from the changelog.
 !searchparse /file "${BUILD_DIR}\CHANGELOG.md" `## [` VERSION_LOG `]`
 # NSIS requires X.X.X.X format in VIProductVersion. Use it everywhere for consistency.
 !define VERSION "${VERSION_LOG}.0"
-
-var SM_Folder
+# User variables.
+Var SM_folder
+Var UIPort
+Var WelcomePortNote
+Var Prev_version
 
 ######################################################################
-
+# Installer file properties
 VIProductVersion "${VERSION}"
 VIAddVersionKey "ProductName"  "${APP_NAME}"
 VIAddVersionKey "CompanyName"  "${COMP_NAME}"
@@ -33,122 +33,145 @@ VIAddVersionKey "FileVersion"  "${VERSION}"
 VIAddVersionKey "ProductVersion" "${VERSION}"
 
 ######################################################################
-
+# Installer settings
 RequestExecutionLevel user
-SetCompressor ZLIB
+SetCompressor LZMA
 Name "${APP_NAME}"
-Caption "${APP_NAME}"
 OutFile "${INSTALLER_NAME}"
-BrandingText "${APP_NAME}"
 XPStyle on
-InstallDirRegKey "${REG_ROOT}" "${REG_APP_PATH}" ""
+InstallDirRegKey "${REG_ROOT}" "${REG_UNINSTALL_PATH}" ""
 InstallDir "$LOCALAPPDATA\Programs\Backrest"
 ManifestDPIAware true
+ShowInstDetails show
+ShowUninstDetails show
+# Include NSIS scripts used by this script.
+!include "MUI2.nsh"
+!include "LogicLib.nsh"
+!include "StrFunc.nsh"
+# Declare used built-in functions.
+${StrStr}
 
 ######################################################################
-
-!include "MUI.nsh"
-
+# GUI pages
+# Interface configuration, applies to all pages.
 !define MUI_ABORTWARNING
 !define MUI_UNABORTWARNING
+!define MUI_COMPONENTSPAGE_NODESC
 
+!define MUI_TEXT_WELCOME_INFO_TEXT "Setup will guide you through the installation of Backrest.$\r$\n$\r$\nBackrest binds to 127.0.0.1:9898 for web UI. You may change the port using BACKREST_PORT environment variable (see installation documentation). If setting the variable, exit and re-run this installer to have it pick up the new value.$\r$\n$\r$\nYou must use a custom port if there are other Backrest instances running concurrently on this system.$WelcomePortNote$\r$\n$\r$\n$_CLICK"
 !insertmacro MUI_PAGE_WELCOME
-
-!ifdef LICENSE_TXT
 !insertmacro MUI_PAGE_LICENSE "${LICENSE_TXT}"
-!endif
-
+!insertmacro MUI_PAGE_COMPONENTS
 !insertmacro MUI_PAGE_DIRECTORY
 
-!ifdef REG_START_MENU
-!define MUI_STARTMENUPAGE_DEFAULTFOLDER "Backrest"
 !define MUI_STARTMENUPAGE_REGISTRY_ROOT "${REG_ROOT}"
-!define MUI_STARTMENUPAGE_REGISTRY_KEY "${UNINSTALL_PATH}"
+!define MUI_STARTMENUPAGE_REGISTRY_KEY "${REG_UNINSTALL_PATH}"
 !define MUI_STARTMENUPAGE_REGISTRY_VALUENAME "${REG_START_MENU}"
-!insertmacro MUI_PAGE_STARTMENU Application $SM_Folder
-!endif
-
+# Get Start Menu folder name from the dialog screen and store it in a variable.
+!insertmacro MUI_PAGE_STARTMENU "Application" $SM_folder
 !insertmacro MUI_PAGE_INSTFILES
 
 !define MUI_FINISHPAGE_RUN "$INSTDIR\${MAIN_APP_EXE}"
+!define MUI_FINISHPAGE_RUN_TEXT "Start ${APP_NAME} (runs in the system tray)"
+# Use the built-in readme option to open the app URL.
+!define MUI_FINISHPAGE_SHOWREADME http://localhost:$UIPort/
+!define MUI_FINISHPAGE_SHOWREADME_TEXT "Open Backrest user interface"
 !insertmacro MUI_PAGE_FINISH
 
+# Uninstall pages.
 !insertmacro MUI_UNPAGE_CONFIRM
-
 !insertmacro MUI_UNPAGE_INSTFILES
-
 !insertmacro MUI_UNPAGE_FINISH
 
 !insertmacro MUI_LANGUAGE "English"
 
 ######################################################################
+# Functions
+# Have to define the function this way to allow re-using it in the uninstall section.
+!macro KillProc UN
+Function ${UN}KillProc
+DetailPrint "Stopping Backrest if it is running..."
+# Gracefully attempt to stop Backrest process in the current session.
+# Do it 5 times 1 second apart, then kill forcefully.
+nsExec::ExecToLog 'powershell.exe -Command "while ((Get-Process -Name backrest-windows-tray -ea SilentlyContinue | where { $$_.SessionId -eq (Get-Process -Id $$PID).SessionId }) -and ($$count -ne 5)) { $$count++ ; taskkill /FI """USERNAME eq $$([Environment]::UserName)""" /IM backrest-windows-tray.exe; sleep 1 }; if ($$count -eq 5) { Stop-Process -Name backrest-windows-tray }" '
+FunctionEnd
+!macroend
+!insertmacro KillProc ""
+!insertmacro KillProc "un."
+
+Function .onInit
+# Old pre-1.6.2 installer installed into C:\Program Files; override the default path when upgrading.
+# $R0, $R1 etc are registers; used here as local temp variables.
+ReadRegStr $Prev_version ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayVersion"
+${If} "$Prev_version" == "00.00.00.00"
+StrCpy $INSTDIR "$LOCALAPPDATA\Programs\Backrest"
+${EndIf}
+# Read BACKREST_PORT environment variable.
+ReadEnvStr $R1 BACKREST_PORT
+${If} "$R1" == ""
+  # Use the default port and welcome text if the var is empty.
+  StrCpy $UIPort "9898"
+  StrCpy $WelcomePortNote ""
+${Else}
+  # Extract substring starting with a colon, assign to $R2.
+  ${StrStr} $R2 $R1 ":"
+  # Assign the value to $UIPort, omitting the first character (:).
+  StrCpy $UIPort $R2 "" 1
+  StrCpy $WelcomePortNote "$\r$\n$\r$\nNOTE: detected BACKREST_PORT variable present. Will use port $UIPort for shortcuts."
+${EndIf}
+FunctionEnd
 
-Section -MainProgram
+######################################################################
+# Sections
+Section "Application files"
+SectionIn RO
 ${INSTALL_TYPE}
+Call KillProc
+# Clean up remnants from the old installer (except for items in "Program Files" which would require elevation).
+${If} "$Prev_version" == "00.00.00.00"
+  Delete "$DESKTOP\${APP_NAME} Console.lnk"
+  Delete "$SMPROGRAMS\$SM_Folder\${APP_NAME} Website.lnk"
+  Delete "$SMPROGRAMS\${APP_NAME}\Uninstall ${APP_NAME}.lnk"
+  DeleteRegKey ${REG_ROOT} "Software\Microsoft\Windows\CurrentVersion\App Paths\${MAIN_APP_EXE}"
+${EndIf}
+
 SetOverwrite ifnewer
 SetOutPath "$INSTDIR"
 File "${BUILD_DIR}\backrest.exe"
 File "${BUILD_DIR}\backrest-windows-tray.exe"
 File "${BUILD_DIR}\LICENSE"
 File "${BUILD_DIR}\icon.ico"
-SectionEnd
+WriteUninstaller "$INSTDIR\uninstall.exe"
 
-######################################################################
+# Start Menu shortcuts
+!insertmacro MUI_STARTMENU_WRITE_BEGIN "Application"
+CreateDirectory "$SMPROGRAMS\$SM_folder"
+CreateShortCut "$SMPROGRAMS\$SM_folder\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
+CreateShortCut "$SMPROGRAMS\$SM_folder\${APP_NAME} UI.lnk" "http://localhost:$UIPort/" "" "$INSTDIR\icon.ico" 0
+WriteIniStr "$SMPROGRAMS\$SM_folder\${APP_NAME} website.url" "InternetShortcut" "URL" "${WEB_SITE}"
+!insertmacro MUI_STARTMENU_WRITE_END
 
-Section "Run at startup"
-CreateDirectory $SMSTARTUP
-CreateShortcut "$SMSTARTUP\$(^Name).lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
+# Registry entries
+WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayName" "${APP_NAME}"
+WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "UninstallString" "$INSTDIR\uninstall.exe"
+WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayIcon" "$INSTDIR\icon.ico"
+WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "DisplayVersion" "${VERSION}"
+WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "Publisher" "${COMP_NAME}"
+WriteRegStr ${REG_ROOT} "${REG_UNINSTALL_PATH}" "URLInfoAbout" "${WEB_SITE}"
 SectionEnd
 
-Section -Icons_Reg
-SetOutPath "$INSTDIR"
-WriteUninstaller "$INSTDIR\uninstall.exe"
-
-!ifdef REG_START_MENU
-!insertmacro MUI_STARTMENU_WRITE_BEGIN Application
-CreateDirectory "$SMPROGRAMS\$SM_Folder"
-CreateShortCut "$SMPROGRAMS\$SM_Folder\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
-CreateShortCut "$DESKTOP\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
-CreateShortCut "$DESKTOP\${APP_NAME} UI.lnk" "http://localhost:9898/" "" "$INSTDIR\icon.ico" 0
-CreateShortCut "$SMPROGRAMS\$SM_Folder\Uninstall ${APP_NAME}.lnk" "$INSTDIR\uninstall.exe" "" "$INSTDIR\icon.ico" 0
-
-!ifdef WEB_SITE
-WriteIniStr "$INSTDIR\${APP_NAME} website.url" "InternetShortcut" "URL" "${WEB_SITE}"
-CreateShortCut "$SMPROGRAMS\$SM_Folder\${APP_NAME} Website.lnk" "$INSTDIR\${APP_NAME} website.url" "" "$INSTDIR\icon.ico" 0
-!endif
-!insertmacro MUI_STARTMENU_WRITE_END
-!endif
-
-!ifndef REG_START_MENU
-CreateDirectory "$SMPROGRAMS\Backrest"
-CreateShortCut "$SMPROGRAMS\Backrest\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "${INSTDIR}\icon.ico" 0
-CreateShortCut "$DESKTOP\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "${INSTDIR}\icon.ico" 0
-CreateShortCut "$SMPROGRAMS\Backrest\Uninstall ${APP_NAME}.lnk" "$INSTDIR\uninstall.exe" "" "${INSTDIR}\icon.ico" 0
-
-!ifdef WEB_SITE
-WriteIniStr "$INSTDIR\${APP_NAME} website.url" "InternetShortcut" "URL" "${WEB_SITE}"
-CreateShortCut "$SMPROGRAMS\Backrest\${APP_NAME} Website.lnk" "$INSTDIR\${APP_NAME} website.url" "" "${INSTDIR}\icon.ico" 0
-!endif
-!endif
-
-WriteRegStr ${REG_ROOT} "${REG_APP_PATH}" "" "$INSTDIR\${MAIN_APP_EXE}"
-WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "DisplayName" "${APP_NAME}"
-WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "UninstallString" "$INSTDIR\uninstall.exe"
-WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "DisplayIcon" "$INSTDIR\icon.ico"
-WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "DisplayVersion" "${VERSION}"
-WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "Publisher" "${COMP_NAME}"
-
-!ifdef WEB_SITE
-WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "URLInfoAbout" "${WEB_SITE}"
-!endif
+Section "Run application at startup (recommended)"
+CreateDirectory $SMSTARTUP
+CreateShortcut "$SMSTARTUP\${APP_NAME}.lnk" "$INSTDIR\${MAIN_APP_EXE}" "" "$INSTDIR\icon.ico" 0
 SectionEnd
 
-######################################################################
+Section "Desktop shortcut"
+CreateShortCut "$DESKTOP\${APP_NAME} UI.lnk" "http://localhost:$UIPort/" "" "$INSTDIR\icon.ico" 0
+SectionEnd
 
-Section Uninstall
+Section "Uninstall"
 ${INSTALL_TYPE}
-ExecWait "TASKKILL /IM backrest-windows-tray.exe"
-Sleep 1000
+Call un.KillProc
 Delete "$INSTDIR\LICENSE"
 Delete "$INSTDIR\icon.ico"
 Delete "$INSTDIR\install.lock"
@@ -156,39 +179,16 @@ Delete "$INSTDIR\restic*.exe"
 Delete "$INSTDIR\backrest.exe"
 Delete "$INSTDIR\backrest-windows-tray.exe"
 Delete "$INSTDIR\uninstall.exe"
-Delete "$SMSTARTUP\$(^Name).lnk"
-!ifdef WEB_SITE
-Delete "$INSTDIR\${APP_NAME} website.url"
-!endif
-
 RmDir "$INSTDIR"
-
-!ifdef REG_START_MENU
-!insertmacro MUI_STARTMENU_GETFOLDER "Application" $SM_Folder
-Delete "$SMPROGRAMS\$SM_Folder\${APP_NAME}.lnk"
-Delete "$SMPROGRAMS\$SM_Folder\Uninstall ${APP_NAME}.lnk"
-Delete "$DESKTOP\${APP_NAME}.lnk"
+# Get Start Menu folder name from the registry and delete shortcuts.
+!insertmacro MUI_STARTMENU_GETFOLDER "Application" $SM_folder
+Delete "$SMPROGRAMS\$SM_folder\${APP_NAME}.lnk"
+Delete "$SMPROGRAMS\$SM_folder\${APP_NAME} UI.lnk"
+Delete "$SMPROGRAMS\$SM_folder\${APP_NAME} website.url"
+RmDir "$SMPROGRAMS\$SM_folder"
+# Startup and desktop shortcuts
+Delete "$SMSTARTUP\${APP_NAME}.lnk"
 Delete "$DESKTOP\${APP_NAME} UI.lnk"
-!ifdef WEB_SITE
-Delete "$SMPROGRAMS\$SM_Folder\${APP_NAME} Website.lnk"
-!endif
-Delete "$DESKTOP\${APP_NAME}.lnk"
-
-
-RmDir "$SMPROGRAMS\$SM_Folder"
-!endif
-
-!ifndef REG_START_MENU
-Delete "$SMPROGRAMS\Backrest\${APP_NAME}.lnk"
-Delete "$SMPROGRAMS\Backrest\Uninstall ${APP_NAME}.lnk"
-!ifdef WEB_SITE
-Delete "$SMPROGRAMS\Backrest\${APP_NAME} Website.lnk"
-!endif
-Delete "$DESKTOP\${APP_NAME}.lnk"
-
-RmDir "$SMPROGRAMS\Backrest"
-!endif
-
-DeleteRegKey ${REG_ROOT} "${REG_APP_PATH}"
-DeleteRegKey ${REG_ROOT} "${UNINSTALL_PATH}"
+# Registry
+DeleteRegKey ${REG_ROOT} "${REG_UNINSTALL_PATH}"
 SectionEnd