diff --git a/AK/Time.h b/AK/Time.h
index 967b9c13912..b7c2ed32553 100644
--- a/AK/Time.h
+++ b/AK/Time.h
@@ -13,9 +13,10 @@
 #include <AK/Platform.h>
 #include <AK/Types.h>
 #ifdef AK_OS_WINDOWS
+// https://learn.microsoft.com/en-us/windows/win32/api/winsock/ns-winsock-timeval
 struct timeval {
-    long tv_sec;
-    long tv_usec;
+    long tv_sec { 0 };
+    long tv_usec { 0 };
 };
 #else
 #    include <sys/time.h>
diff --git a/Libraries/CMakeLists.txt b/Libraries/CMakeLists.txt
index 921cef93f70..afe56a5c5c3 100644
--- a/Libraries/CMakeLists.txt
+++ b/Libraries/CMakeLists.txt
@@ -1,3 +1,14 @@
+add_subdirectory(LibRegex)
+add_subdirectory(LibTest)
+add_subdirectory(LibTextCodec)
+add_subdirectory(LibUnicode)
+add_subdirectory(LibURL)
+
+# FIXME: Increase support for building targets on Windows
+if (WIN32 AND ENABLE_WINDOWS_CI)
+    return()
+endif()
+
 add_subdirectory(LibCompress)
 add_subdirectory(LibCrypto)
 add_subdirectory(LibDiff)
@@ -7,16 +18,11 @@ add_subdirectory(LibHTTP)
 add_subdirectory(LibIPC)
 add_subdirectory(LibJS)
 add_subdirectory(LibLine)
-add_subdirectory(LibRegex)
 add_subdirectory(LibRequests)
 add_subdirectory(LibRIFF)
 add_subdirectory(LibSyntax)
-add_subdirectory(LibTest)
-add_subdirectory(LibTextCodec)
 add_subdirectory(LibThreading)
 add_subdirectory(LibTLS)
-add_subdirectory(LibUnicode)
-add_subdirectory(LibURL)
 add_subdirectory(LibWasm)
 add_subdirectory(LibWebSocket)
 add_subdirectory(LibXML)
diff --git a/Libraries/LibTest/CMakeLists.txt b/Libraries/LibTest/CMakeLists.txt
index 12793f5bffa..c58bea2cd7b 100644
--- a/Libraries/LibTest/CMakeLists.txt
+++ b/Libraries/LibTest/CMakeLists.txt
@@ -2,8 +2,6 @@ add_library(LibTestMain OBJECT TestMain.cpp AssertionHandler.cpp)
 
 target_link_libraries(LibTestMain PUBLIC GenericClangPlugin)
 
-add_library(JavaScriptTestRunnerMain OBJECT JavaScriptTestRunnerMain.cpp)
-
 set(SOURCES
     TestSuite.cpp
 )
@@ -12,3 +10,10 @@ add_library(LibTest ${SOURCES})
 lagom_generate_export_header(LibTest test)
 target_link_libraries(LibTest PRIVATE AK LibCore LibFileSystem)
 set_target_properties(LibTest PROPERTIES OUTPUT_NAME lagom-test)
+
+# FIXME: Increase support for building targets on Windows
+if (WIN32 AND ENABLE_WINDOWS_CI)
+    return()
+endif()
+
+add_library(JavaScriptTestRunnerMain OBJECT JavaScriptTestRunnerMain.cpp)
diff --git a/Tests/AK/CMakeLists.txt b/Tests/AK/CMakeLists.txt
index e94d82b5209..a36e4a20469 100644
--- a/Tests/AK/CMakeLists.txt
+++ b/Tests/AK/CMakeLists.txt
@@ -20,6 +20,7 @@ set(AK_TEST_SOURCES
     TestDisjointChunks.cpp
     TestDistinctNumeric.cpp
     TestDoublyLinkedList.cpp
+    TestDuration.cpp
     TestEndian.cpp
     TestEnumBits.cpp
     TestEnumerate.cpp
@@ -44,7 +45,6 @@ set(AK_TEST_SOURCES
     TestIntrusiveRedBlackTree.cpp
     TestJSON.cpp
     TestLEB128.cpp
-    TestLexicalPath.cpp
     TestMemory.cpp
     TestMemoryStream.cpp
     TestNeverDestroyed.cpp
@@ -70,7 +70,6 @@ set(AK_TEST_SOURCES
     TestStringFloatingPointConversions.cpp
     TestStringUtils.cpp
     TestStringView.cpp
-    TestDuration.cpp
     TestTrie.cpp
     TestTuple.cpp
     TestTypeTraits.cpp
@@ -83,10 +82,21 @@ set(AK_TEST_SOURCES
     TestWeakPtr.cpp
 )
 
+# FIXME: LexicalPathWindows has some parenting and path parts sizing inconsistencies with LexicalPath, so it deserves
+#  it's own platform-specific tests to avoid if-def soup in the Unix-based tests.
+if(NOT WIN32)
+    list(APPEND AK_TEST_SOURCES TestLexicalPath.cpp)
+endif()
+
 foreach(source IN LISTS AK_TEST_SOURCES)
     serenity_test("${source}" AK)
 endforeach()
 
+if (WIN32)
+    # FIXME: Windows on ARM
+    target_link_libraries(TestUFixedBigInt PRIVATE clang_rt.builtins-x86_64.lib)
+endif()
+
 if (CXX_COMPILER_SUPPORTS_BLOCKS)
     serenity_test(TestFunction.mm AK NAME TestFunction)
     target_link_libraries(TestFunction PRIVATE ${BLOCKS_REQUIRED_LIBRARIES})
diff --git a/Tests/AK/TestDuration.cpp b/Tests/AK/TestDuration.cpp
index 7b7feebaa96..f9b7952dc19 100644
--- a/Tests/AK/TestDuration.cpp
+++ b/Tests/AK/TestDuration.cpp
@@ -7,11 +7,10 @@
 #include <LibTest/TestCase.h>
 
 #include <AK/Time.h>
-#include <sys/time.h>
 
 using AK::Duration;
 
-#if defined(__TIMESIZE) && __TIMESIZE < 64
+#if (defined(__TIMESIZE) && __TIMESIZE < 64) || defined(AK_OS_WINDOWS) // NOTE: See AK/Time.h, on Windows we hardcode to long's for timeval
 #    define TIME_T_IS_32BIT
 #endif
 
diff --git a/Tests/AK/TestFormat.cpp b/Tests/AK/TestFormat.cpp
index 427cd765472..e9678ba35d6 100644
--- a/Tests/AK/TestFormat.cpp
+++ b/Tests/AK/TestFormat.cpp
@@ -9,8 +9,10 @@
 #include <AK/ByteString.h>
 #include <AK/StringBuilder.h>
 #include <AK/Vector.h>
-#include <math.h>
-#include <unistd.h>
+
+#ifdef AK_OS_WINDOWS
+#    include <stdio.h>
+#endif
 
 TEST_CASE(is_integral_works_properly)
 {
@@ -232,8 +234,12 @@ TEST_CASE(file_descriptor)
 {
     char filename[] = "/tmp/test-file-descriptor-XXXXXX";
 
+#ifdef AK_OS_WINDOWS
+    FILE* file = tmpfile();
+#else
     int fd = mkstemp(filename);
     FILE* file = fdopen(fd, "w+");
+#endif
 
     outln(file, "{}", "Hello, World!");
     out(file, "foo");
diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
index 859d9ffdda1..99b011940c6 100644
--- a/Tests/CMakeLists.txt
+++ b/Tests/CMakeLists.txt
@@ -1,4 +1,10 @@
 add_subdirectory(AK)
+
+# FIXME: Increase support for building targets on Windows
+if (WIN32 AND ENABLE_WINDOWS_CI)
+    return()
+endif()
+
 add_subdirectory(LibCrypto)
 add_subdirectory(LibCompress)
 add_subdirectory(LibCore)
diff --git a/Utilities/CMakeLists.txt b/Utilities/CMakeLists.txt
index 013347c6a39..dbe5044d626 100644
--- a/Utilities/CMakeLists.txt
+++ b/Utilities/CMakeLists.txt
@@ -1,3 +1,8 @@
+# FIXME: Increase support for building targets on Windows
+if (WIN32 AND ENABLE_WINDOWS_CI)
+    return()
+endif()
+
 lagom_utility(abench SOURCES abench.cpp LIBS LibMain LibFileSystem LibMedia)
 lagom_utility(dns SOURCES dns.cpp LIBS LibDNS LibMain LibTLS LibCrypto)