diff --git a/win32/installer/hexchat.iss.tt b/win32/installer/hexchat.iss.tt
index 1f2e1491..ad4b6051 100644
--- a/win32/installer/hexchat.iss.tt
+++ b/win32/installer/hexchat.iss.tt
@@ -4,6 +4,9 @@
 ;#define APPARCH "x64"
 ;#define PROJECTDIR "C:\...\hexchat\win32\installer\"
 
+;http://mitrich.net23.net/?/inno-download-plugin.html
+#include <idp.iss>
+
 [Setup]
 AppName=HexChat
 AppVersion={#APPVER}
@@ -57,7 +60,7 @@ Name: "custom"; Description: "Custom Installation"; Flags: iscustom
 Name: "libs"; Description: "HexChat"; Types: normal minimal custom; Flags: fixed
 Name: "gtktheme"; Description: "GTK+ Theme"; Types: normal custom; Flags: disablenouninstallwarning
 Name: "xctext"; Description: "HexChat-Text"; Types: custom; Flags: disablenouninstallwarning
-Name: "xtm"; Description: "HexChat Theme Manager (Requires .NET 4.0)"; Types: normal custom; Flags: disablenouninstallwarning
+Name: "xtm"; Description: "HexChat Theme Manager"; Types: normal custom; Flags: disablenouninstallwarning
 Name: "translations"; Description: "Translations"; Types: normal custom; Flags: disablenouninstallwarning
 Name: "plugins"; Description: "Plugins"; Types: custom; Flags: disablenouninstallwarning
 Name: "plugins\checksum"; Description: "Checksum"; Types: custom; Flags: disablenouninstallwarning
@@ -95,12 +98,11 @@ Root: HKCR; Subkey: ".hct\shell\open\command"; ValueType: string; ValueName: "";
 
 [Run]
 Filename: "{app}\hexchat.exe"; Description: "Run HexChat after closing the Wizard"; Flags: nowait postinstall skipifsilent
-Filename: "https://www.microsoft.com/en-us/download/details.aspx?id=39315"; Description: "Download Visual C++ 2013 Redistributable"; Flags: shellexec runasoriginaluser postinstall skipifsilent
-Filename: "http://www.microsoft.com/en-us/download/details.aspx?id=17851"; Description: "Download .NET 4.0 for theme manager"; Components: xtm; Flags: shellexec runasoriginaluser postinstall skipifsilent
 Filename: "http://docs.hexchat.org/en/latest/changelog.html"; Description: "See what's changed"; Flags: shellexec runasoriginaluser postinstall skipifsilent unchecked
-Filename: "http://hexchat.org/downloads.html"; Description: "Download Perl"; Flags: shellexec runasoriginaluser postinstall skipifsilent unchecked; Components: langs\perl and not langs\python
-Filename: "http://hexchat.org/downloads.html"; Description: "Download Python"; Flags: shellexec runasoriginaluser postinstall skipifsilent unchecked; Components: langs\python and not langs\perl
-Filename: "http://hexchat.org/downloads.html"; Description: "Download Perl and Python"; Flags: shellexec runasoriginaluser postinstall skipifsilent unchecked; Components: langs\perl and langs\python
+Filename: "{tmp}\vcredist.exe"; Parameters: "/install /quiet /norestart"; StatusMsg: "Installing Visual C++ Redist"; Flags: skipifdoesntexist; Tasks: not portable
+Filename: "{tmp}\dotnet4.exe"; Parameters: "/q /norestart"; StatusMsg: "Installing .NET"; Components: xtm; Flags: skipifdoesntexist; Tasks: not portable
+Filename: "{tmp}\perl.msi"; StatusMsg: "Installing Perl"; Components: langs\perl; Flags: shellexec skipifdoesntexist; Tasks: not portable
+Filename: "{tmp}\python.msi"; StatusMsg: "Installing Python"; Components: langs\python; Flags: shellexec skipifdoesntexist; Tasks: not portable
 
 [Files]
 Source: "portable-mode"; DestDir: "{app}"; Tasks: portable
@@ -182,8 +184,89 @@ BeveledLabel= {#APPNAM}
 procedure InitializeWizard;
 begin
 	WizardForm.LicenseAcceptedRadio.Checked := True;
+
+	idpDownloadAfter(wpReady);
 end;
 
+/////////////////////////////////////////////////////////////////////
+function GetSysDir(): String;
+begin
+#if APPARCH != "x64"
+	if IsWin64 then
+		Result := ExpandConstant('{syswow64}\')
+	else
+		Result := ExpandConstant('{sys}\');
+#else
+	Result := ExpandConstant('{sys}\');
+#endif
+end;
+
+/////////////////////////////////////////////////////////////////////
+function CheckDLL(DLLName: String): Boolean;
+var
+	ResultCode: Integer;
+begin
+	if ExecAsOriginalUser(GetSysDir() + 'where.exe', '/Q ' + DLLName,
+						'', SW_HIDE, ewWaitUntilTerminated, ResultCode) then
+		Result := ResultCode = 0 // 0 is success
+	else
+		Result := False;
+end;
+
+/////////////////////////////////////////////////////////////////////
+function CheckVCInstall(): Boolean;
+begin
+	Result := FileExists(GetSysDir() + 'msvcr120.dll');;
+end;
+
+/////////////////////////////////////////////////////////////////////
+function CheckDotNetInstall(): Boolean;
+begin
+	Result := RegKeyExists(HKLM, 'SOFTWARE\Microsoft\NET Framework Setup\NDP\v4');
+end;
+
+/////////////////////////////////////////////////////////////////////
+procedure CurPageChanged(CurPageID: Integer);
+var
+	REDIST: String;
+	PERL: String;
+	PY2: String;
+	PY3: String;
+	DOTNET: String;
+begin
+  if not IsTaskSelected('portable') and (CurPageID = wpReady) then
+  begin
+    idpClearFiles;
+	
+#if APPARCH == "x64"
+	REDIST := 'http://dl.hexchat.net/misc/vcredist_2013_x64.exe';
+	PERL := 'http://dl.hexchat.net/misc/perl/Perl%205.18.0%20x64.msi';
+	PY2 := 'http://python.org/ftp/python/2.7.5/python-2.7.5.amd64.msi';
+	PY3 := 'http://python.org/ftp/python/3.3.2/python-3.3.2.amd64.msi';
+#else
+	REDIST := 'http://dl.hexchat.net/misc/vcredist_2013_x86.exe';
+	PERL := 'http://dl.hexchat.net/misc/perl/Perl%205.18.0%20x86.msi';
+	PY2 := 'http://python.org/ftp/python/2.7.5/python-2.7.5.msi';
+	PY3 := 'http://python.org/ftp/python/3.3.2/python-3.3.2.msi';
+#endif
+	DOTNET := 'http://dl.hexchat.net/misc/dotnet_40.exe';
+
+	if not CheckVCInstall() then
+		idpAddFile(REDIST, ExpandConstant('{tmp}\vcredist.exe'));
+
+	if IsComponentSelected('xtm') and not CheckDotNetInstall() then
+		idpAddFile(DOTNET, ExpandConstant('{tmp}\dotnet4.exe'));
+		
+	if IsComponentSelected('langs\perl') and not CheckDLL('perl518.dll') then
+		idpAddFile(PERL, ExpandConstant('{tmp}\perl.msi'));
+		
+	if IsComponentSelected('langs\python\python2') and not CheckDLL('python27.dll') then
+		idpAddFile(PY2, ExpandConstant('{tmp}\python.msi'));
+		
+	if IsComponentSelected('langs\python\python3') and not CheckDLL('python33.dll') then
+		idpAddFile(PY3, ExpandConstant('{tmp}\python.msi'));
+  end;
+end;
 
 /////////////////////////////////////////////////////////////////////
 // these are required for x86->x64 or reverse upgrades
@@ -211,7 +294,6 @@ begin
 	Result := sUnInstallString;
 end;
 
-
 /////////////////////////////////////////////////////////////////////
 function IsUpgrade(): Boolean;
 begin