diff --git a/engine/CMakeLists.txt b/engine/CMakeLists.txt
index dd2a7cc4..da7a1956 100644
--- a/engine/CMakeLists.txt
+++ b/engine/CMakeLists.txt
@@ -86,7 +86,7 @@ add_library(bald_engine
         ${CMAKE_CURRENT_SOURCE_DIR}/src/core/platform/opengl/buffers/opengl_index_buffer.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/src/core/platform/opengl/buffers/opengl_vertex_array.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/src/core/platform/opengl/shaders/opengl_shader.cpp
-        ${CMAKE_CURRENT_SOURCE_DIR}/src/core/utils/file_manager.cpp
+        src/core/utils/file_manager/file_manager.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/src/core/utils/split_string.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/src/core/utils/timer.cpp)
 
diff --git a/engine/src/core/platform/opengl/shaders/opengl_shader.cpp b/engine/src/core/platform/opengl/shaders/opengl_shader.cpp
index 4536686b..e606ff20 100644
--- a/engine/src/core/platform/opengl/shaders/opengl_shader.cpp
+++ b/engine/src/core/platform/opengl/shaders/opengl_shader.cpp
@@ -4,7 +4,7 @@
 
 #include "opengl_shader.h"
 #include <unordered_map>
-#include "file_manager.h"
+#include "src/core/utils/file_manager/file_manager.h"
 #include "pch.h"
 #include "glad/glad.h"
 
@@ -101,7 +101,7 @@ namespace Bald::Platform::Graphics {
         vertexShader = glCreateShader(GL_VERTEX_SHADER);
 
         std::string vertexShaderSource = Utils::FileManager::ReadFile(m_VertexPath,
-                                                                      Utils::FileManager::Size::SMALL_FILE);
+                                                                      Utils::FileManager::Size::small_file);
         const char* vertexData = vertexShaderSource.c_str();
 
         glShaderSource(vertexShader, 1, &vertexData, nullptr);
@@ -127,7 +127,7 @@ namespace Bald::Platform::Graphics {
         fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
 
         std::string fragmentShaderSource = Utils::FileManager::ReadFile(m_FragmentPath,
-                                                                        Utils::FileManager::Size::SMALL_FILE);
+                                                                        Utils::FileManager::Size::small_file);
         const char* fragmentData = fragmentShaderSource.c_str();
 
         glShaderSource(fragmentShader, 1, &fragmentData, nullptr);
diff --git a/engine/src/core/utils/file_manager.cpp b/engine/src/core/utils/file_manager/file_manager.cpp
similarity index 69%
rename from engine/src/core/utils/file_manager.cpp
rename to engine/src/core/utils/file_manager/file_manager.cpp
index a503498a..2bc1049e 100644
--- a/engine/src/core/utils/file_manager.cpp
+++ b/engine/src/core/utils/file_manager/file_manager.cpp
@@ -13,7 +13,7 @@
 namespace Bald::Utils {
 
     std::string FileManager::ReadFile(const char* filePath, Size size) {
-        if (size == Size::SMALL_FILE)
+        if (size == Size::small_file)
             return ReadSmallFile(filePath);
         return ReadBigFile(filePath);
     }
@@ -74,10 +74,32 @@ namespace Bald::Utils {
         return result;
     }
 
-#elif WINDOWS
+#else
+#include <fstream>
     std::string FileManager::ReadBigFile(const char *filePath) {
-        CORE_LOG_INFO("[FILE_MANAGER] Error: Windows implementation is not done yet! Using slower reading method!");
-        ReadSmallFile(filePath);
+//        CORE_LOG_INFO("[FILE_MANAGER] Error: Windows implementation is not done yet! Using slower reading method!");
+//        ReadSmallFile(filePath);
+    std::streampos begin,end;
+    std::ifstream file(filePath, std::ios::in);
+    char* buffer;
+    if(file.is_open()){
+        begin = file.tellg();
+        file.seekg (0, std::ios::end);
+        end = file.tellg();
+        auto size = static_cast<size_t>(end-begin);
+        buffer = new char[static_cast<unsigned long>(size)];
+        std::memset(buffer, '\0', static_cast<unsigned long>(size));
+        file.seekg(0, std::ios::beg);
+        file.read(buffer, static_cast<std::streamsize>(size));
+        file.close();
+        std::string result(buffer);
+        delete[] buffer;
+        return result;
+    }
+
+    CORE_LOG_WARN("[FileManager] Couldn't get size of the file. Check if the file exists at path: " + static_cast<std::string>(filePath));
+    return "[FileManager] Couldn't get size of the file. Check if the file exists at path: " + static_cast<std::string>(filePath);
+
     }
 #endif
 
diff --git a/engine/src/core/utils/file_manager.h b/engine/src/core/utils/file_manager/file_manager.h
similarity index 98%
rename from engine/src/core/utils/file_manager.h
rename to engine/src/core/utils/file_manager/file_manager.h
index b877e0d5..59adf5fd 100644
--- a/engine/src/core/utils/file_manager.h
+++ b/engine/src/core/utils/file_manager/file_manager.h
@@ -19,7 +19,7 @@ namespace Bald::Utils {
          * ENUM which determines size of file and therefor methods, which will be used to read it
          */
         enum class Size : char {
-            SMALL_FILE, BIG_FILE
+            small_file, big_file
         };
     public:
 
diff --git a/engine/tests/test_file_manager.cpp b/engine/tests/test_file_manager.cpp
index 49a13cdf..f4a23b82 100644
--- a/engine/tests/test_file_manager.cpp
+++ b/engine/tests/test_file_manager.cpp
@@ -4,32 +4,32 @@
 
 #include "core/pch.h"
 #include "gtest/gtest.h"
-#include "utils/file_manager.h"
+#include "src/core/utils/file_manager/file_manager.h"
 
 TEST(FileManager, GoodSmallFileOpening) { //NOLINT
 
-    std::string file_result = Bald::Utils::FileManager::ReadFile("../engine/test_file_manager.txt", Bald::Utils::FileManager::Size::SMALL_FILE);
+    std::string file_result = Bald::Utils::FileManager::ReadFile("../engine/test_file_manager.txt", Bald::Utils::FileManager::Size::small_file);
 
     EXPECT_EQ("plik testowy\ndo odczytu", file_result);
 }
 
 TEST(FileManager, GoodBigFileOpening) { //NOLINT
 
-    std::string file_result = Bald::Utils::FileManager::ReadFile("../engine/test_file_manager.txt", Bald::Utils::FileManager::Size::BIG_FILE);
+    std::string file_result = Bald::Utils::FileManager::ReadFile("../engine/test_file_manager.txt", Bald::Utils::FileManager::Size::big_file);
 
     EXPECT_EQ("plik testowy\ndo odczytu", file_result);
 }
 
 TEST(FileManager, WrongSmallFileOpening) { //NOLINT
 
-    std::string file_result = Bald::Utils::FileManager::ReadFile("no_such_file.cpp", Bald::Utils::FileManager::Size::SMALL_FILE);
+    std::string file_result = Bald::Utils::FileManager::ReadFile("no_such_file.cpp", Bald::Utils::FileManager::Size::small_file);
 
     EXPECT_EQ("[FileManager] Couldn't open the file at path: no_such_file.cpp", file_result);
 }
 
 TEST(FileManager, WrongBigFileOpening) { //NOLINT
 
-    std::string file_result = Bald::Utils::FileManager::ReadFile("no_such_file.cpp", Bald::Utils::FileManager::Size::BIG_FILE);
+    std::string file_result = Bald::Utils::FileManager::ReadFile("no_such_file.cpp", Bald::Utils::FileManager::Size::big_file);
 
     EXPECT_EQ("[FileManager] Couldn't get size of the file. Check if the file exists at path: no_such_file.cpp", file_result);
 }