Function FuncUpgrade

  ReadRegDWORD $R0 HKLM "Software\HT\RCS" "installed"
  
  ; RCS is not installed
  IntCmp $R0 1 +2 0 0
    Abort

  StrCpy $upgradeComponents ""

  ; check which components we have
  ReadRegDWORD $R0 HKLM "Software\HT\RCS" "collector"
  IntCmp $R0 1 0 +4 +4
    StrCpy $upgradeComponents "$upgradeComponentsCollector$\r"
    Push ${BST_CHECKED}
    Pop $installCollector 

  ReadRegDWORD $R0 HKLM "Software\HT\RCS" "master"
  IntCmp $R0 1 0 +4 +4
    StrCpy $upgradeComponents "$upgradeComponentsMaster$\r"
    Push ${BST_CHECKED}
    Pop $installMaster 

  ReadRegDWORD $R0 HKLM "Software\HT\RCS" "shard"
  IntCmp $R0 1 0 +4 +4
    StrCpy $upgradeComponents "$upgradeComponentsShard$\r"
    Push ${BST_CHECKED}
    Pop $installShard 

  !insertmacro MUI_HEADER_TEXT "Installation Type" "Upgrade"

  nsDialogs::Create /NOUNLOAD 1018
  
  CreateFont $R1 "Arial" "8" "600"
  
  ${NSD_CreateLabel} 0 5u 100% 20u "The setup has detected that at least one RCS component is installed on this machine."
  ${NSD_CreateLabel} 0 25u 100% 20u  "If you continue the following components will be upgraded:"
  ${NSD_CreateLabel} 20u 40u 100% 50u  $upgradeComponents
  Pop $1
  SendMessage $1 ${WM_SETFONT} $R1 0
  
  ${NSD_CreateCheckBox} 20u 100u 200u 12u "YES, Upgrade."
  Pop $1
  SendMessage $1 ${WM_SETFONT} $R1 0
 
  nsDialogs::Show
FunctionEnd

Function FuncUpgradeLeave
  ${NSD_GetState} $1 $installUPGRADE

  ${If} $installUPGRADE != ${BST_CHECKED}
    MessageBox MB_OK|MB_ICONSTOP "Please check the upgrade option. If you don't want to upgrade exit the installer now."
    Abort
  ${EndIf}
  
  SetCurInstType 1
  
FunctionEnd

.