diff --git a/compiler/cc.v b/compiler/cc.v
index ee56eed215..8272a440d5 100644
--- a/compiler/cc.v
+++ b/compiler/cc.v
@@ -32,7 +32,16 @@ fn (v mut V) cc() {
 	linux_host := os.user_os() == 'linux'
 	v.log('cc() isprod=$v.pref.is_prod outname=$v.out_name')
 	mut a := [v.pref.cflags, '-std=gnu11', '-w'] // arguments for the C compiler
-	flags := v.table.flags.join(' ')
+
+	mut seenflags := map[string]int
+	mut uniqueflags := []string
+	for f in v.table.flags {
+		seenflags[ f ] = seenflags[ f ] + 1
+		if seenflags[ f ] > 1 { continue }
+		uniqueflags << f
+	}
+	flags := uniqueflags.join(' ')
+
 	//mut shared := ''
 	if v.pref.is_so {
 		a << '-shared -fPIC '// -Wl,-z,defs'
diff --git a/compiler/cgen.v b/compiler/cgen.v
index 22892a5324..bd86ecb064 100644
--- a/compiler/cgen.v
+++ b/compiler/cgen.v
@@ -246,18 +246,19 @@ fn build_thirdparty_obj_file(flag string) {
 		return
 	}
 	println('$obj_path not found, building it...')
-	parent := obj_path.all_before_last('/').trim_space()
+	parent := os.dir( obj_path )
 	files := os.ls(parent)
-	//files := os.ls(parent).filter(_.ends_with('.c'))  TODO
 	mut cfiles := ''
 	for file in files {
 		if file.ends_with('.c') {
-			cfiles += parent + '/' + file + ' '
+			cfiles += '"' + os.realpath( parent + os.PathSeparator + file ) + '" '
 		}
 	}
 	cc := find_c_compiler()
 	cc_thirdparty_options := find_c_compiler_thirdparty_options()
-	res := os.exec('$cc $cc_thirdparty_options -c -o $obj_path $cfiles') or {
+	cmd := '$cc $cc_thirdparty_options -c -o "$obj_path" $cfiles'
+	res := os.exec(cmd) or {
+		println('failed thirdparty object build cmd: $cmd')
 		cerror(err)
 		return
 	}
diff --git a/compiler/cheaders.v b/compiler/cheaders.v
index 3dc700699b..8424b37f98 100644
--- a/compiler/cheaders.v
+++ b/compiler/cheaders.v
@@ -43,7 +43,9 @@ CommonCHeaders = '
 #include <windows.h>
 
 // must be included after <windows.h>
+#ifndef __TINYC__
 #include <shellapi.h>
+#endif
 
 #include <io.h> // _waccess
 #include <fcntl.h> // _O_U8TEXT
@@ -54,8 +56,8 @@ CommonCHeaders = '
 #define _Atomic volatile
 
 // MSVC cannot parse some things properly
-#undef EMPTY_STRUCT_DECLARATION
-#define EMPTY_STRUCT_DECLARATION void *____dummy_variable
+//#undef EMPTY_STRUCT_DECLARATION
+//#define EMPTY_STRUCT_DECLARATION void *____dummy_variable
 #undef OPTION_CAST
 #define OPTION_CAST(x)
 #endif
diff --git a/compiler/comptime.v b/compiler/comptime.v
index 7cdbfb8bf8..a503ff798b 100644
--- a/compiler/comptime.v
+++ b/compiler/comptime.v
@@ -171,6 +171,8 @@ fn (p mut Parser) chash() {
 		p.log('adding flag "$flag"')
 		// `@VROOT/thirdparty/glad/glad.o`, make sure it exists, otherwise build it
 		if (has_vroot || has_vmod) && flag.contains('.o') {
+			flag = os.realpath( flag )
+			//println( 'absolute filepath to objectfile is now: $flag | os is: $p.os ')
 			if p.os == .msvc {
 				build_thirdparty_obj_file_with_msvc(flag)
 			}
diff --git a/compiler/msvc.v b/compiler/msvc.v
index f7834ddf85..a0a9a56591 100644
--- a/compiler/msvc.v
+++ b/compiler/msvc.v
@@ -5,6 +5,7 @@ import os
 #flag windows -l shell32
 
 struct MsvcResult {
+	full_cl_exe_path string
 	exe_path string
 
 	um_lib_path string
@@ -187,6 +188,7 @@ fn find_msvc() ?MsvcResult {
 		}
 
 		return MsvcResult {
+			full_cl_exe_path: os.realpath( vs.exe_path + os.PathSeparator + 'cl.exe' )
 			exe_path: vs.exe_path,
 
 			um_lib_path: wk.um_lib_path,
@@ -214,13 +216,13 @@ pub fn (v mut V) cc_msvc() {
 	r := find_msvc() or {
 		// TODO: code reuse
 		if !v.pref.is_debug && v.out_name_c != 'v.c' && v.out_name_c != 'v_macos.c' {
-			os.rm('.$v.out_name_c')
+			os.rm(v.out_name_c)
 		}
 		cerror('Cannot find MSVC on this OS.')
 		return
 	}
 
-	out_name_obj := v.out_name_c + '.obj'
+	out_name_obj := os.realpath( v.out_name_c + '.obj' )
 
 	// Default arguments
 
@@ -228,7 +230,7 @@ pub fn (v mut V) cc_msvc() {
 	// -w: no warnings
 	// 2 unicode defines
 	// /Fo sets the object file name - needed so we can clean up after ourselves properly
-	mut a := ['-w', '/we4013', '/volatile:ms', '/D_UNICODE', '/DUNICODE', '/Fo$out_name_obj']
+	mut a := ['-w', '/we4013', '/volatile:ms', '/D_UNICODE', '/DUNICODE', '/Fo"$out_name_obj"']
 
 	if v.pref.is_prod {
 		a << '/O2'
@@ -249,15 +251,18 @@ pub fn (v mut V) cc_msvc() {
 		v.out_name = v.out_name + '.exe'
 	}
 
-	mut libs := ''// builtin.o os.o http.o etc
+	v.out_name = os.realpath( v.out_name )
+
+	mut alibs := []string // builtin.o os.o http.o etc
 	if v.pref.build_mode == .build {
 	}
 	else if v.pref.build_mode == .embed_vlib {
 		// 
 	}
 	else if v.pref.build_mode == .default_mode {
-		libs = '"$ModPath/vlib/builtin.obj"'
-		if !os.file_exists(libs) {
+		b := os.realpath( '$ModPath/vlib/builtin.obj' )
+		alibs << '"$b"'
+		if !os.file_exists(b) {
 			println('`builtin.obj` not found')
 			exit(1)
 		}
@@ -265,7 +270,7 @@ pub fn (v mut V) cc_msvc() {
 			if imp == 'webview' {
 				continue
 			}
-			libs += ' "$ModPath/vlib/${imp}.obj"'
+			alibs << '"' + os.realpath( '$ModPath/vlib/${imp}.obj' ) + '"'
 		}
 	}
 
@@ -275,7 +280,7 @@ pub fn (v mut V) cc_msvc() {
 
 	// The C file we are compiling
 	//a << '"$TmpPath/$v.out_name_c"'
-	a << '"$v.out_name_c"'
+	a << '"' + os.realpath( v.out_name_c ) + '"'
 
 	// Emily:
 	// Not all of these are needed (but the compiler should discard them if they are not used)
@@ -296,13 +301,17 @@ pub fn (v mut V) cc_msvc() {
 		'vcruntime.lib',
 	]
 
+	mut inc_paths := []string{}
 	mut lib_paths := []string{}
 	mut other_flags := []string{}
 
 	// Emily:
 	// this is a hack to try and support -l -L and object files
 	// passed on the command line
+	mut seenflags := map[string]int // no need to add the same flags more than once
 	for f in v.table.flags {
+		seenflags[ f ] = seenflags[ f ] + 1
+		if seenflags[ f ] > 1 { continue }
 		// People like to put multiple flags per line (which really complicates things)
 		// ...so we need to handle that
 		mut rest := f
@@ -345,7 +354,12 @@ pub fn (v mut V) cc_msvc() {
 
 		for flag in flags {
 			fl := flag.f
-			arg := flag.arg
+			mut arg := flag.arg
+			if fl == '-I' || fl == '-L' {
+				arg = os.realpath( arg )
+			}
+			//println('fl: $fl | flag arg: $arg')
+
 			// We need to see if the flag contains -l
 			// -l isnt recognised and these libs will be passed straight to the linker
 			// by the compiler
@@ -353,14 +367,23 @@ pub fn (v mut V) cc_msvc() {
 				if arg.ends_with('.dll') {
 					cerror('MSVC cannot link against a dll (`#flag -l $arg`)')
 				}
-
 				// MSVC has no method of linking against a .dll
 				// TODO: we should look for .defs aswell
 				lib_lib := arg + '.lib'
 				real_libs << lib_lib
-			} 
+			}
+			else if fl == '-I' {
+				inc_paths << ' -I "$arg" '
+			}
 			else if fl == '-L' {
-				lib_paths << f.right(2).trim_space()
+				lpath := f.right(2).trim_space()
+				lib_paths << lpath
+				lib_paths << lpath + os.PathSeparator + 'msvc'
+				// The above allows putting msvc specific .lib files in a subfolder msvc/ ,
+				// where gcc will NOT find them, but cl will do...
+				// NB: gcc is smart enough to not need .lib files at all in most cases, the .dll is enough.
+				// When both a msvc .lib file and .dll file are present in the same folder,
+				// as for example for glfw3, compilation with gcc would fail.
 			}
 			else if arg.ends_with('.o') {
 				// msvc expects .obj not .o
@@ -374,7 +397,12 @@ pub fn (v mut V) cc_msvc() {
 	}
 
 	// Include the base paths
-	a << '-I "$r.ucrt_include_path" -I "$r.vs_include_path" -I "$r.um_include_path" -I "$r.shared_include_path"'
+	a << ' -I "$r.ucrt_include_path" '
+	a << ' -I "$r.vs_include_path" '
+	a << ' -I "$r.um_include_path" '
+	a << ' -I "$r.shared_include_path" '
+
+	a << inc_paths
 
 	a << other_flags
 
@@ -383,14 +411,14 @@ pub fn (v mut V) cc_msvc() {
 
 	a << '/link'
 	a << '/NOLOGO'
-	a << '/OUT:$v.out_name'
+	a << '/OUT:"$v.out_name"'
 	a << '/LIBPATH:"$r.ucrt_lib_path"'
 	a << '/LIBPATH:"$r.um_lib_path"'
 	a << '/LIBPATH:"$r.vs_lib_path"'
 	a << '/INCREMENTAL:NO' // Disable incremental linking
 
 	for l in lib_paths {
-		a << '/LIBPATH:"$l"'
+		a << '/LIBPATH:"' + os.realpath(l) + '"'
 	}
 
 	if !v.pref.is_prod {
@@ -401,16 +429,13 @@ pub fn (v mut V) cc_msvc() {
 
 	args := a.join(' ')
 
-	// println('$args')
-	// println('$exe_path')
-
-	escaped_path := r.exe_path
-
-	cmd := '""$escaped_path\\cl.exe" $args"'
-
+	cmd := '""$r.full_cl_exe_path" $args"' 
+	// It is hard to see it at first, but the quotes above ARE balanced :-| ... 
+	// Also the double quotes at the start ARE needed.
 	if v.pref.show_c_cmd || v.pref.is_verbose {
-		println('\n==========')
+		println('\n========== cl cmd line:')
 		println(cmd)
+		println('==========\n')
 	}
 
 	// println('$cmd')
@@ -427,11 +452,11 @@ pub fn (v mut V) cc_msvc() {
 	// println('C OUTPUT:')
 
 	if !v.pref.is_debug && v.out_name_c != 'v.c' && v.out_name_c != 'v_macos.c' {
-		os.rm('.$v.out_name_c')
+		os.rm(v.out_name_c)
 	}
 
 	// Always remove the object file - it is completely unnecessary
-	os.rm('$out_name_obj')
+	os.rm(out_name_obj)
 }
 
 fn build_thirdparty_obj_file_with_msvc(flag string) {
@@ -448,24 +473,29 @@ fn build_thirdparty_obj_file_with_msvc(flag string) {
 	}
 
 	if os.file_exists(obj_path) {
+		println('$obj_path already build.')
 		return 
 	} 
+
 	println('$obj_path not found, building it (with msvc)...') 
-	parent := obj_path.all_before_last('/').trim_space() 
+	parent := os.dir( obj_path )
 	files := os.ls(parent)
 
 	mut cfiles := '' 
 	for file in files {
 		if file.ends_with('.c') { 
-			cfiles += parent + '/' + file + ' ' 
+			cfiles += '"' + os.realpath( parent + os.PathSeparator + file )  + '" '
 		} 
 	}
 
 	include_string := '-I "$msvc.ucrt_include_path" -I "$msvc.vs_include_path" -I "$msvc.um_include_path" -I "$msvc.shared_include_path"'
 
-	println('$cfiles')
+	//println('cfiles: $cfiles')
 
-	res := os.exec('""$msvc.exe_path\\cl.exe" /volatile:ms /Z7 $include_string /c $cfiles /Fo"$obj_path" /D_UNICODE /DUNICODE"') or {
+	cmd := '""$msvc.full_cl_exe_path" /volatile:ms /Z7 $include_string /c $cfiles /Fo"$obj_path" /D_UNICODE /DUNICODE"'
+	//NB: the quotes above ARE balanced.
+	println('thirdparty cmd line: $cmd')
+	res := os.exec(cmd) or {
 		cerror(err)
 		return
 	}
diff --git a/thirdparty/glfw/msvc/glfw3.lib b/thirdparty/glfw/msvc/glfw3.lib
new file mode 100644
index 0000000000..9051189fc3
Binary files /dev/null and b/thirdparty/glfw/msvc/glfw3.lib differ
diff --git a/vlib/builtin/string.v b/vlib/builtin/string.v
index 503a3380e2..232206406b 100644
--- a/vlib/builtin/string.v
+++ b/vlib/builtin/string.v
@@ -151,6 +151,7 @@ pub fn (s string) u32() u32 {
 
 pub fn (s string) u64() u64 {
 	return C.strtoull(s.str, 0, 0)
+	//return C.atoll(s.str) // temporary fix for tcc on windows.
 }
 
 // ==