diff --git a/Greenshot-OCR-Plugin/Greenshot-OCR-Plugin.csproj b/Greenshot-OCR-Plugin/Greenshot-OCR-Plugin.csproj
index a79afe556..d8c16fd65 100644
--- a/Greenshot-OCR-Plugin/Greenshot-OCR-Plugin.csproj
+++ b/Greenshot-OCR-Plugin/Greenshot-OCR-Plugin.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <ProjectGuid>{C6988EE8-2FEE-4349-9F09-F9628A0D8965}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -15,6 +15,7 @@
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <RunPostBuildEvent>OnBuildSuccess</RunPostBuildEvent>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <OutputPath>bin\Debug\</OutputPath>
diff --git a/Greenshot/Greenshot.csproj b/Greenshot/Greenshot.csproj
index 50415ce52..c468e7c6a 100644
--- a/Greenshot/Greenshot.csproj
+++ b/Greenshot/Greenshot.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="3.5">
   <PropertyGroup>
     <ProjectGuid>{CD642BF4-D815-4D67-A0B5-C69F0B8231AF}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -16,6 +16,7 @@
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
     <ApplicationManifest>greenshot.manifest</ApplicationManifest>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <OutputPath>bin\Debug\</OutputPath>
diff --git a/GreenshotExternalCommandPlugin/GreenshotExternalCommandPlugin.csproj b/GreenshotExternalCommandPlugin/GreenshotExternalCommandPlugin.csproj
index 6151f481b..55c86ccde 100644
--- a/GreenshotExternalCommandPlugin/GreenshotExternalCommandPlugin.csproj
+++ b/GreenshotExternalCommandPlugin/GreenshotExternalCommandPlugin.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <ProjectGuid>{47F23C86-604E-4CC3-8767-B3D4088F30BB}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
diff --git a/GreenshotImgurPlugin/GreenshotImgurPlugin.csproj b/GreenshotImgurPlugin/GreenshotImgurPlugin.csproj
index 01f229929..85000515f 100644
--- a/GreenshotImgurPlugin/GreenshotImgurPlugin.csproj
+++ b/GreenshotImgurPlugin/GreenshotImgurPlugin.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <ProjectGuid>{80D8DEB9-94E3-4876-8CCA-2DF1ED5F2C50}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -15,6 +15,7 @@
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <RunPostBuildEvent>OnBuildSuccess</RunPostBuildEvent>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <OutputPath>bin\Debug\</OutputPath>
@@ -56,7 +57,7 @@
     <Compile Include="Forms\ImgurForm.cs">
       <SubType>Form</SubType>
     </Compile>
-    <Compile Include="Forms\ImgurHistory.cs" >
+    <Compile Include="Forms\ImgurHistory.cs">
       <SubType>Form</SubType>
     </Compile>
     <Compile Include="Forms\ImgurHistory.Designer.cs">
diff --git a/GreenshotJiraPlugin/GreenshotJiraPlugin.csproj b/GreenshotJiraPlugin/GreenshotJiraPlugin.csproj
index 710ec2872..9a1b04cae 100644
--- a/GreenshotJiraPlugin/GreenshotJiraPlugin.csproj
+++ b/GreenshotJiraPlugin/GreenshotJiraPlugin.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <ProjectGuid>{19FEEF09-313F-43C7-819D-F1BCA782B08B}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -15,6 +15,7 @@
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <RunPostBuildEvent>OnBuildSuccess</RunPostBuildEvent>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <OutputPath>bin\Debug\</OutputPath>
diff --git a/GreenshotNetworkImportPlugin/GreenshotNetworkImportPlugin.csproj b/GreenshotNetworkImportPlugin/GreenshotNetworkImportPlugin.csproj
index 350d8e037..fe172bc1d 100644
--- a/GreenshotNetworkImportPlugin/GreenshotNetworkImportPlugin.csproj
+++ b/GreenshotNetworkImportPlugin/GreenshotNetworkImportPlugin.csproj
@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>GreenshotNetworkImportPlugin</RootNamespace>
     <AssemblyName>GreenshotNetworkImportPlugin</AssemblyName>
-    <TargetFrameworkVersion>v3.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <AppDesignerFolder>Properties</AppDesignerFolder>
diff --git a/GreenshotPlugin/GreenshotPlugin.csproj b/GreenshotPlugin/GreenshotPlugin.csproj
index dbe8a9707..cbd927f7d 100644
--- a/GreenshotPlugin/GreenshotPlugin.csproj
+++ b/GreenshotPlugin/GreenshotPlugin.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <ProjectGuid>{5B924697-4DCD-4F98-85F1-105CB84B7341}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -15,6 +15,7 @@
     <NoStdLib>False</NoStdLib>
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <OutputPath>bin\Debug\</OutputPath>
diff --git a/GreenshotTest/GreenshotTest.csproj b/GreenshotTest/GreenshotTest.csproj
index 348b57bd0..9c60619f6 100644
--- a/GreenshotTest/GreenshotTest.csproj
+++ b/GreenshotTest/GreenshotTest.csproj
@@ -14,6 +14,7 @@
     <NoStdLib>False</NoStdLib>
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <OutputPath>bin\Debug\</OutputPath>
diff --git a/PluginExample/PluginExample.csproj b/PluginExample/PluginExample.csproj
index b202b6349..950211f52 100644
--- a/PluginExample/PluginExample.csproj
+++ b/PluginExample/PluginExample.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <ProjectGuid>{6BD38118-B27F-43A1-951C-FB6464D39260}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -15,6 +15,7 @@
     <NoStdLib>False</NoStdLib>
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Platform)' == 'x86' ">
     <PlatformTarget>x86</PlatformTarget>