diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8375ea518..2cef41b83 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -62,7 +62,7 @@ file (GLOB AWS_COMMON_EXTERNAL_SRC
 option(AWS_NUM_CPU_CORES "Number of CPU cores of the target machine. Useful when cross-compiling." 0)
 
 if (WIN32)
-    set(WINDOWS_KERNEL_LIB "Kernel32" CACHE STRING "The name of the kernel library to link against (default: Kernel32)")
+    set(WINDOWS_KERNEL_LIB "kernel32" CACHE STRING "The name of the kernel library to link against (default: kernel32)")
 
     file(GLOB AWS_COMMON_OS_HEADERS
         "include/aws/common/windows/*"
@@ -81,7 +81,7 @@ if (WIN32)
     endif ()
 
     list(APPEND PLATFORM_DEFINES WINDOWS_KERNEL_LIB=${WINDOWS_KERNEL_LIB})
-    list(APPEND PLATFORM_LIBS BCrypt ${WINDOWS_KERNEL_LIB} Ws2_32 Shlwapi)
+    list(APPEND PLATFORM_LIBS bcrypt ${WINDOWS_KERNEL_LIB} ws2_32 shlwapi)
 else ()
     file(GLOB AWS_COMMON_OS_HEADERS
         "include/aws/common/posix/*"
diff --git a/cmake/AwsFeatureTests.cmake b/cmake/AwsFeatureTests.cmake
index 6b02be718..82b495f93 100644
--- a/cmake/AwsFeatureTests.cmake
+++ b/cmake/AwsFeatureTests.cmake
@@ -35,7 +35,7 @@ if(NOT CMAKE_CROSSCOMPILING)
 endif()
 
 check_c_source_compiles("
-    #include <Windows.h>
+    #include <windows.h>
     #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
     int main() {
         return 0;
diff --git a/include/aws/common/condition_variable.h b/include/aws/common/condition_variable.h
index 317dedb9c..ba5984cb8 100644
--- a/include/aws/common/condition_variable.h
+++ b/include/aws/common/condition_variable.h
@@ -33,7 +33,7 @@ struct aws_condition_variable {
  * You can do something like struct aws_condition_variable var =
  * AWS_CONDITION_VARIABLE_INIT;
  *
- * If on Windows and you get an error about AWS_CONDITION_VARIABLE_INIT being undefined, please include Windows.h to get
+ * If on Windows and you get an error about AWS_CONDITION_VARIABLE_INIT being undefined, please include windows.h to get
  * CONDITION_VARIABLE_INIT.
  */
 #ifdef _WIN32
diff --git a/include/aws/common/mutex.h b/include/aws/common/mutex.h
index b64e5e32f..3a491abc9 100644
--- a/include/aws/common/mutex.h
+++ b/include/aws/common/mutex.h
@@ -8,7 +8,7 @@
 
 #include <aws/common/common.h>
 #ifdef _WIN32
-/* NOTE: Do not use this macro before including Windows.h */
+/* NOTE: Do not use this macro before including windows.h */
 #    define AWSMUTEX_TO_WINDOWS(pMutex) (PSRWLOCK) & (pMutex)->mutex_handle
 #else
 #    include <pthread.h>
diff --git a/include/aws/common/rw_lock.h b/include/aws/common/rw_lock.h
index f8d86ae2a..538841f63 100644
--- a/include/aws/common/rw_lock.h
+++ b/include/aws/common/rw_lock.h
@@ -8,7 +8,7 @@
 
 #include <aws/common/common.h>
 #ifdef _WIN32
-/* NOTE: Do not use this macro before including Windows.h */
+/* NOTE: Do not use this macro before including windows.h */
 #    define AWSSRW_TO_WINDOWS(pCV) (PSRWLOCK) pCV
 #else
 #    include <pthread.h>
diff --git a/include/aws/testing/aws_test_harness.h b/include/aws/testing/aws_test_harness.h
index 2f743be54..7ef7b71e0 100644
--- a/include/aws/testing/aws_test_harness.h
+++ b/include/aws/testing/aws_test_harness.h
@@ -501,7 +501,7 @@ static inline int s_aws_run_test_case(struct aws_test_harness *harness) {
 /* https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences */
 #ifdef _WIN32
 
-#    include <Windows.h>
+#    include <windows.h>
 
 #    ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
 #        define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x0004
diff --git a/source/allocator.c b/source/allocator.c
index e444d282a..4f47542a5 100644
--- a/source/allocator.c
+++ b/source/allocator.c
@@ -12,7 +12,7 @@
 #include <stdlib.h>
 
 #ifdef _WIN32
-#    include <Windows.h>
+#    include <windows.h>
 #endif
 
 #ifdef __MACH__
diff --git a/source/common.c b/source/common.c
index 79e301539..ce48bd11c 100644
--- a/source/common.c
+++ b/source/common.c
@@ -14,7 +14,7 @@
 #include <stdlib.h>
 
 #ifdef _WIN32
-#    include <Windows.h>
+#    include <windows.h>
 #else
 #    include <dlfcn.h>
 #endif
diff --git a/source/windows/clock.c b/source/windows/clock.c
index b7b0b3820..3c36aa15e 100644
--- a/source/windows/clock.c
+++ b/source/windows/clock.c
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0.
  */
 
-#include <Windows.h>
+#include <windows.h>
 #include <aws/common/clock.h>
 
 static const uint64_t FILE_TIME_TO_NS = 100;
diff --git a/source/windows/condition_variable.c b/source/windows/condition_variable.c
index 5a989ead0..07d6a0cdd 100644
--- a/source/windows/condition_variable.c
+++ b/source/windows/condition_variable.c
@@ -8,7 +8,7 @@
 #include <aws/common/clock.h>
 #include <aws/common/mutex.h>
 
-#include <Windows.h>
+#include <windows.h>
 
 #define AWSCV_TO_WINDOWS(pCV) (PCONDITION_VARIABLE) & (pCV)->condition_handle
 
diff --git a/source/windows/device_random.c b/source/windows/device_random.c
index 0233d6890..99de174f2 100644
--- a/source/windows/device_random.c
+++ b/source/windows/device_random.c
@@ -7,7 +7,7 @@
 #include <aws/common/byte_buf.h>
 #include <aws/common/thread.h>
 
-#include <Windows.h>
+#include <windows.h>
 #include <bcrypt.h>
 
 static BCRYPT_ALG_HANDLE s_alg_handle = NULL;
diff --git a/source/windows/file.c b/source/windows/file.c
index 47e874f07..07f73c29d 100644
--- a/source/windows/file.c
+++ b/source/windows/file.c
@@ -8,7 +8,7 @@
 #include <aws/common/logging.h>
 #include <aws/common/string.h>
 
-#include <Shlwapi.h>
+#include <shlwapi.h>
 #include <errno.h>
 #include <io.h>
 #include <stdio.h>
diff --git a/source/windows/mutex.c b/source/windows/mutex.c
index aedefd2af..75e7a23d1 100644
--- a/source/windows/mutex.c
+++ b/source/windows/mutex.c
@@ -6,7 +6,7 @@
 #include <aws/common/mutex.h>
 #include <aws/common/thread.h>
 
-#include <Windows.h>
+#include <windows.h>
 
 /* Convert a string from a macro to a wide string */
 #define WIDEN2(s) L## #s
diff --git a/source/windows/rw_lock.c b/source/windows/rw_lock.c
index 36cc81aa9..5bf73c773 100644
--- a/source/windows/rw_lock.c
+++ b/source/windows/rw_lock.c
@@ -6,7 +6,7 @@
 #include <aws/common/rw_lock.h>
 #include <aws/common/thread.h>
 
-#include <Windows.h>
+#include <windows.h>
 #include <synchapi.h>
 
 /* Convert a string from a macro to a wide string */
diff --git a/source/windows/thread.c b/source/windows/thread.c
index 9124afefb..b053cc411 100644
--- a/source/windows/thread.c
+++ b/source/windows/thread.c
@@ -10,7 +10,8 @@
 #include <aws/common/private/thread_shared.h>
 #include <aws/common/string.h>
 
-#include <Windows.h>
+#include <windows.h>
+#include <winnt.h>
 
 #include <inttypes.h>