--- a/browser/installer/windows/nsis/stub.nsi
+++ b/browser/installer/windows/nsis/stub.nsi
@@ -42,28 +42,25 @@ Var FontInstalling
 Var FontBlurb
 Var FontFooter
 Var FontCheckbox
 
 Var CanWriteToInstallDir
 Var HasRequiredSpaceAvailable
 Var IsDownloadFinished
 Var DownloadSizeBytes
-Var HalfOfDownload
 Var DownloadReset
 Var ExistingTopDir
 Var SpaceAvailableBytes
 Var InitialInstallDir
 Var HandleDownload
 Var CanSetAsDefault
 Var InstallCounterStep
-Var InstallStepSize
 Var InstallTotalSteps
 Var ProgressCompleted
-Var ProgressTotal
 
 Var ExitCode
 Var FirefoxLaunchCode
 
 Var StartDownloadPhaseTickCount
 ; Since the Intro and Options pages can be displayed multiple times the total
 ; seconds spent on each of these pages is reported.
 Var IntroPhaseSeconds
@@ -90,17 +87,16 @@ Var OpenedDownloadPage
 Var DownloadServerIP
 Var PostSigningData
 Var PreviousInstallDir
 Var PreviousInstallArch
 Var ProfileCleanupPromptType
 Var ProfileCleanupHeaderString
 Var ProfileCleanupButtonString
 Var AppLaunchWaitTickCount
-Var AppLaunchWaitStepSize
 
 ; Uncomment the following to prevent pinging the metrics server when testing
 ; the stub installer
 ;!define STUB_DEBUG
 
 !define StubURLVersion "v8"
 
 ; Successful install exit code
@@ -156,55 +152,42 @@ Var AppLaunchWaitStepSize
 !define DownloadRetryIntervalMS 3000
 
 ; Interval for the download timer
 !define DownloadIntervalMS 200
 
 ; Interval for the install timer
 !define InstallIntervalMS 100
 
-; The first step for the install progress bar. By starting with a large step
-; immediate feedback is given to the user.
-!define InstallProgressFirstStep 20
-
-; The finish step size to quickly increment the progress bar after the
-; installation has finished.
-!define InstallProgressFinishStep 40
-
 ; Number of steps for the install progress.
 ; This might not be enough when installing on a slow network drive so it will
-; fallback to downloading the full installer if it reaches this number. The size
-; of the install progress step is increased when the full installer finishes
-; instead of waiting.
+; fallback to downloading the full installer if it reaches this number.
 
-; Approximately 150 seconds with a 100 millisecond timer and a first step of 20
-; as defined by InstallProgressFirstStep.
-!define /math InstallCleanTotalSteps ${InstallProgressFirstStep} + 1500
+; Approximately 150 seconds with a 100 millisecond timer.
+!define InstallCleanTotalSteps 1500
 
-; Approximately 165 seconds (minus 0.2 seconds for each file that is removed)
-; with a 100 millisecond timer and a first step of 20 as defined by
-; InstallProgressFirstStep .
-!define /math InstallPaveOverTotalSteps ${InstallProgressFirstStep} + 1800
+; Approximately 165 seconds with a 100 millisecond timer.
+!define InstallPaveOverTotalSteps 1650
 
-; 5 more seconds at the end of the progress bar to wait for the app to launch.
-!define AppLaunchWaitSteps 500
-
-; Number of steps per interval to advance the progress bar. Calibrate this based
-; on how long the progress bar should spend filling up while awaiting app launch.
-!define AppLaunchWaitStepSizeMultiplier 20
+; Blurb duty cycle
+!define BlurbDisplayMS 19500
+!define BlurbBlankMS 500
 
 ; Interval between checks for the application window and progress bar updates.
 !define AppLaunchWaitIntervalMS 100
 
 ; Total time to wait for the application to start before just exiting.
 !define AppLaunchWaitTimeoutMS 10000
 
-; Blurb duty cycle
-!define BlurbDisplayMS 19500
-!define BlurbBlankMS 500
+; Maximum value of the download/install/launch progress bar, and the end values
+; for each individual stage.
+!define PROGRESS_BAR_TOTAL_STEPS 500 
+!define PROGRESS_BAR_DOWNLOAD_END_STEP 300
+!define PROGRESS_BAR_INSTALL_END_STEP 475
+!define PROGRESS_BAR_APP_LAUNCH_END_STEP 500
 
 ; Amount of physical memory required for the 64-bit build to be selected (2 GB).
 ; Machines with this or less RAM get the 32-bit build, even with a 64-bit OS.
 !define RAM_NEEDED_FOR_64BIT 0x80000000
 
 ; Attempt to elevate Standard Users in addition to users that
 ; are a member of the Administrators group.
 !define NONADMIN_ELEVATE
@@ -558,17 +541,16 @@ Function .onGUIEnd
   ${UnloadUAC}
 FunctionEnd
 
 Function .onUserAbort
   ${NSD_KillTimer} StartDownload
   ${NSD_KillTimer} OnDownload
   ${NSD_KillTimer} CheckInstall
   ${NSD_KillTimer} FinishInstall
-  ${NSD_KillTimer} FinishProgressBar
   ${NSD_KillTimer} DisplayDownloadError
   ${NSD_KillTimer} NextBlurb
   ${NSD_KillTimer} ClearBlurb
 
   ${If} "$IsDownloadFinished" != ""
     Call DisplayDownloadError
   ${Else}
     Call SendPing
@@ -899,27 +881,17 @@ Function StartDownload
   ${NSD_CreateTimer} OnDownload ${DownloadIntervalMS}
   ${If} ${FileExists} "$INSTDIR\${TO_BE_DELETED}"
     RmDir /r "$INSTDIR\${TO_BE_DELETED}"
   ${EndIf}
 FunctionEnd
 
 Function SetProgressBars
   SendMessage $Progressbar ${PBM_SETPOS} $ProgressCompleted 0
-  ${ITBL3SetProgressValue} "$ProgressCompleted" "$ProgressTotal"
-FunctionEnd
-
-Function RemoveFileProgressCallback
-  IntOp $InstallCounterStep $InstallCounterStep + 2
-  System::Int64Op $ProgressCompleted + $InstallStepSize
-  Pop $ProgressCompleted
-  Call SetProgressBars
-  System::Int64Op $ProgressCompleted + $InstallStepSize
-  Pop $ProgressCompleted
-  Call SetProgressBars
+  ${ITBL3SetProgressValue} "$ProgressCompleted" "${PROGRESS_BAR_TOTAL_STEPS}"
 FunctionEnd
 
 Function NextBlurb
   ${NSD_KillTimer} NextBlurb
 
   IntOp $CurrentBlurbIdx $CurrentBlurbIdx + 1
   IntOp $CurrentBlurbIdx $CurrentBlurbIdx % 3
 
@@ -1015,31 +987,20 @@ Function OnDownload
         ${NSD_CreateTimer} DisplayDownloadError ${InstallIntervalMS}
       ${Else}
         ${NSD_CreateTimer} StartDownload ${DownloadIntervalMS}
       ${EndIf}
       Return
     ${EndIf}
 
     StrCpy $DownloadSizeBytes "$4"
-    System::Int64Op $4 / 2
-    Pop $HalfOfDownload
-    System::Int64Op $HalfOfDownload / $InstallTotalSteps
-    Pop $InstallStepSize
-    StrCpy $AppLaunchWaitStepSize $InstallStepSize
     SendMessage $Progressbar ${PBM_SETMARQUEE} 0 0 ; start=1|stop=0 interval(ms)=+N
     ${RemoveStyle} $Progressbar ${PBS_MARQUEE}
-    System::Int64Op $HalfOfDownload + $DownloadSizeBytes
-    Pop $ProgressTotal
-    System::Int64Op $AppLaunchWaitStepSize * ${AppLaunchWaitSteps}
-    Pop $R0
-    System::Int64Op $ProgressTotal + $R0
-    Pop $ProgressTotal
     StrCpy $ProgressCompleted 0
-    SendMessage $Progressbar ${PBM_SETRANGE32} $ProgressCompleted $ProgressTotal
+    SendMessage $Progressbar ${PBM_SETRANGE32} $ProgressCompleted ${PROGRESS_BAR_TOTAL_STEPS}
   ${EndIf}
 
   ; Don't update the status until after the download starts
   ${If} $2 != 0
   ${AndIf} "$4" == ""
     Return
   ${EndIf}
 
@@ -1057,20 +1018,16 @@ Function OnDownload
     ${EndIf}
     Return
   ${EndIf}
 
   ${If} $IsDownloadFinished != "true"
     ${If} $2 == 0
       ${NSD_KillTimer} OnDownload
       StrCpy $IsDownloadFinished "true"
-      ; The first step of the install progress bar is determined by the
-      ; InstallProgressFirstStep define and provides the user with immediate
-      ; feedback.
-      StrCpy $InstallCounterStep "${InstallProgressFirstStep}"
       System::Call "kernel32::GetTickCount()l .s"
       Pop $EndDownloadPhaseTickCount
 
       StrCpy $DownloadedBytes "$DownloadSizeBytes"
 
       ; When a download has finished handle the case where the  downloaded size
       ; is less than the minimum expected size or greater than the maximum
       ; expected size during the download.
@@ -1085,23 +1042,19 @@ Function OnDownload
         ${Else}
           ${NSD_CreateTimer} StartDownload ${DownloadIntervalMS}
         ${EndIf}
         Return
       ${EndIf}
 
       ; Update the progress bars first in the UI change so they take affect
       ; before other UI changes.
-      StrCpy $ProgressCompleted "$DownloadSizeBytes"
+      StrCpy $ProgressCompleted "${PROGRESS_BAR_DOWNLOAD_END_STEP}"
       Call SetProgressBars
-      System::Int64Op $InstallStepSize * ${InstallProgressFirstStep}
-      Pop $R9
-      System::Int64Op $ProgressCompleted + $R9
-      Pop $ProgressCompleted
-      Call SetProgressBars
+
       ; Disable the Cancel button during the install
       GetDlgItem $5 $HWNDPARENT 2
       EnableWindow $5 0
 
       ; Open a handle to prevent modification of the full installer
       StrCpy $R9 "${INVALID_HANDLE_VALUE}"
       System::Call 'kernel32::CreateFileW(w "$PLUGINSDIR\download.exe", \
                                           i ${GENERIC_READ}, \
@@ -1170,18 +1123,17 @@ Function OnDownload
       WriteINIStr "$PLUGINSDIR\${CONFIG_INI}" "Install" "MaintenanceService" "false"
 !endif
 
       ; Delete the taskbar shortcut history to ensure we do the right thing based on
       ; the config file above.
       ${GetShortcutsLogPath} $0
       Delete "$0"
 
-      GetFunctionAddress $0 RemoveFileProgressCallback
-      ${RemovePrecompleteEntries} $0
+      ${RemovePrecompleteEntries} "false"
 
       ; Delete the install.log and let the full installer create it. When the
       ; installer closes it we can detect that it has completed.
       Delete "$INSTDIR\install.log"
 
       ; Delete firefox.exe.moz-upgrade and firefox.exe.moz-delete if it exists
       ; since it being present will require an OS restart for the full
       ; installer.
@@ -1189,22 +1141,21 @@ Function OnDownload
       Delete "$INSTDIR\${FileMainEXE}.moz-delete"
 
       System::Call "kernel32::GetTickCount()l .s"
       Pop $EndPreInstallPhaseTickCount
 
       Exec "$\"$PLUGINSDIR\download.exe$\" /INI=$PLUGINSDIR\${CONFIG_INI}"
       ${NSD_CreateTimer} CheckInstall ${InstallIntervalMS}
     ${Else}
-      ${If} $HalfOfDownload != "true"
-      ${AndIf} $3 > $HalfOfDownload
-        StrCpy $HalfOfDownload "true"
-      ${EndIf}
       StrCpy $DownloadedBytes "$3"
-      StrCpy $ProgressCompleted "$DownloadedBytes"
+      System::Int64Op $DownloadedBytes * ${PROGRESS_BAR_DOWNLOAD_END_STEP}
+      Pop $ProgressCompleted
+      System::Int64Op $ProgressCompleted / $DownloadSizeBytes
+      Pop $ProgressCompleted
       Call SetProgressBars
     ${EndIf}
   ${EndIf}
 FunctionEnd
 
 Function SendPing
   ${NSD_KillTimer} NextBlurb
   ${NSD_KillTimer} ClearBlurb
@@ -1480,18 +1431,17 @@ Function CheckInstall
     ; Close the handle that prevents modification of the full installer
     System::Call 'kernel32::CloseHandle(i $HandleDownload)'
     StrCpy $ExitCode "${ERR_INSTALL_TIMEOUT}"
     ; Use a timer so the UI has a chance to update
     ${NSD_CreateTimer} DisplayDownloadError ${InstallIntervalMS}
     Return
   ${EndIf}
 
-  System::Int64Op $ProgressCompleted + $InstallStepSize
-  Pop $ProgressCompleted
+  IntOp $ProgressCompleted $ProgressCompleted + 1
   Call SetProgressBars
 
   ${If} ${FileExists} "$INSTDIR\install.log"
     Delete "$INSTDIR\install.tmp"
     CopyFiles /SILENT "$INSTDIR\install.log" "$INSTDIR\install.tmp"
 
     ; The unfocus and refocus that happens approximately here is caused by the
     ; installer calling SHChangeNotify to refresh the shortcut icons.
@@ -1504,62 +1454,32 @@ Function CheckInstall
       ${NSD_KillTimer} CheckInstall
       ; Close the handle that prevents modification of the full installer
       System::Call 'kernel32::CloseHandle(i $HandleDownload)'
       Rename "$INSTDIR\install.tmp" "$INSTDIR\install.log"
       Delete "$PLUGINSDIR\download.exe"
       Delete "$PLUGINSDIR\${CONFIG_INI}"
       System::Call "kernel32::GetTickCount()l .s"
       Pop $EndInstallPhaseTickCount
-      System::Int64Op $InstallStepSize * ${InstallProgressFinishStep}
-      Pop $InstallStepSize
-      ${NSD_CreateTimer} FinishInstall ${InstallIntervalMS}
+      Call FinishInstall
     ${EndUnless}
   ${EndIf}
 FunctionEnd
 
 Function FinishInstall
-  ; The full installer has completed but the progress bar still needs to finish
-  ; so increase the size of the step.
-  IntOp $InstallCounterStep $InstallCounterStep + ${InstallProgressFinishStep}
-  ${If} $InstallTotalSteps < $InstallCounterStep
-    StrCpy $InstallCounterStep "$InstallTotalSteps"
-  ${EndIf}
-
-  ${If} $InstallTotalSteps != $InstallCounterStep
-    System::Int64Op $ProgressCompleted + $InstallStepSize
-    Pop $ProgressCompleted
-    Call SetProgressBars
-    Return
-  ${EndIf}
-
-  ${NSD_KillTimer} FinishInstall
+  StrCpy $ProgressCompleted "${PROGRESS_BAR_INSTALL_END_STEP}"
+  Call SetProgressBars
 
   ${If} ${FileExists} "$INSTDIR\${FileMainEXE}.moz-upgrade"
     Delete "$INSTDIR\${FileMainEXE}"
     Rename "$INSTDIR\${FileMainEXE}.moz-upgrade" "$INSTDIR\${FileMainEXE}"
   ${EndIf}
 
   StrCpy $ExitCode "${ERR_SUCCESS}"
 
-  StrCpy $InstallCounterStep 0
-  ${NSD_CreateTimer} FinishProgressBar ${InstallIntervalMS}
-FunctionEnd
-
-Function FinishProgressBar
-  IntOp $InstallCounterStep $InstallCounterStep + 1
-
-  ${If} $InstallCounterStep < 10
-    Return
-  ${EndIf}
-
-  ${NSD_KillTimer} FinishProgressBar
-  ${NSD_KillTimer} NextBlurb
-  ${NSD_KillTimer} ClearBlurb
-
   Call CopyPostSigningData
   Call LaunchApp
 FunctionEnd
 
 Function RelativeGotoPage
   IntCmp $R9 0 0 Move Move
   StrCmp $R9 "X" 0 Move
   StrCpy $R9 "120"
@@ -1691,37 +1611,35 @@ Function LaunchAppFromElevatedProcess
 FunctionEnd
 
 Function WaitForAppLaunch
   FindWindow $0 "${MainWindowClass}"
   FindWindow $1 "${DialogWindowClass}"
   ${If} $0 <> 0
   ${OrIf} $1 <> 0
     ${NSD_KillTimer} WaitForAppLaunch
-    StrCpy $ProgressCompleted "$ProgressTotal"
+    StrCpy $ProgressCompleted "${PROGRESS_BAR_APP_LAUNCH_END_STEP}"
     Call SetProgressBars
     Call SendPing
     Return
   ${EndIf}
 
   IntOp $AppLaunchWaitTickCount $AppLaunchWaitTickCount + 1
   IntOp $0 $AppLaunchWaitTickCount * ${AppLaunchWaitIntervalMS}
   ${If} $0 >= ${AppLaunchWaitTimeoutMS}
     ; We've waited an unreasonably long time, so just exit.
     ${NSD_KillTimer} WaitForAppLaunch
     Call SendPing
     Return
   ${EndIf}
 
-  ${If} $AppLaunchWaitTickCount < ${AppLaunchWaitSteps}
-    IntOp $0 $AppLaunchWaitStepSize * ${AppLaunchWaitStepSizeMultiplier}
-    System::Int64Op $ProgressCompleted + $0
-    Pop $ProgressCompleted
+  ${If} $ProgressCompleted < ${PROGRESS_BAR_APP_LAUNCH_END_STEP}
+    IntOp $ProgressCompleted $ProgressCompleted + 1
+    Call SetProgressBars
   ${EndIf}
-  Call SetProgressBars
 FunctionEnd
 
 Function CopyPostSigningData
   ${LineRead} "$EXEDIR\postSigningData" "1" $PostSigningData
   ${If} ${Errors}
     ClearErrors
     StrCpy $PostSigningData "0"
   ${Else}