diff --git a/src/pkg/os/Makefile b/src/pkg/os/Makefile
index fa92c76..b69ac24 100644
--- a/src/pkg/os/Makefile
+++ b/src/pkg/os/Makefile
@@ -19,4 +19,21 @@
 	time.go\
 	types.go\
 
+GOFILES_freebsd=\
+	file_unix.go\
+
+GOFILES_darwin=\
+	file_unix.go\
+
+GOFILES_linux=\
+	file_unix.go\
+
+GOFILES_nacl=\
+	file_unix.go\
+
+GOFILES_mingw=\
+	file_mingw.go\
+
+GOFILES+=$(GOFILES_$(GOOS))
+
 include ../../Make.pkg
diff --git a/src/pkg/os/dir_mingw.go b/src/pkg/os/dir_mingw.go
index e7711f0..0d8267b 100644
--- a/src/pkg/os/dir_mingw.go
+++ b/src/pkg/os/dir_mingw.go
@@ -5,5 +5,13 @@
 package os
 
 func (file *File) Readdirnames(count int) (names []string, err Error) {
-	panic("windows Readdirnames not implemented")
+	fis, e := file.Readdir(count)
+	if e != nil {
+		return nil, e
+	}
+	names = make([]string, len(fis))
+	for i, fi := range fis {
+		names[i] = fi.Name
+	}
+	return names, nil
 }
diff --git a/src/pkg/os/file.go b/src/pkg/os/file.go
index 561f36c..f4af42f 100644
--- a/src/pkg/os/file.go
+++ b/src/pkg/os/file.go
@@ -11,13 +11,6 @@
 	"syscall"
 )
 
-// Auxiliary information if the File describes a directory
-type dirInfo struct {
-	buf  []byte // buffer for directory I/O
-	nbuf int    // length of buf; return value from Getdirentries
-	bufp int    // location of next record in buf.
-}
-
 // File represents an open file descriptor.
 type File struct {
 	fd      int
@@ -68,41 +61,6 @@
 	O_CREATE   = O_CREAT            // create a new file if none exists.
 )
 
-// Open opens the named file with specified flag (O_RDONLY etc.) and perm, (0666 etc.)
-// if applicable.  If successful, methods on the returned File can be used for I/O.
-// It returns the File and an Error, if any.
-func Open(name string, flag int, perm int) (file *File, err Error) {
-	r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, perm)
-	if e != 0 {
-		return nil, &PathError{"open", name, Errno(e)}
-	}
-
-	// There's a race here with fork/exec, which we are
-	// content to live with.  See ../syscall/exec.go
-	if syscall.O_CLOEXEC == 0 { // O_CLOEXEC not supported
-		syscall.CloseOnExec(r)
-	}
-
-	return NewFile(r, name), nil
-}
-
-// Close closes the File, rendering it unusable for I/O.
-// It returns an Error, if any.
-func (file *File) Close() Error {
-	if file == nil || file.fd < 0 {
-		return EINVAL
-	}
-	var err Error
-	if e := syscall.Close(file.fd); e != 0 {
-		err = &PathError{"close", file.name, Errno(e)}
-	}
-	file.fd = -1 // so it can't be closed again
-
-	// no need for a finalizer anymore
-	runtime.SetFinalizer(file, nil)
-	return err
-}
-
 type eofError int
 
 func (eofError) String() string { return "EOF" }
@@ -302,34 +260,6 @@
 	return fileInfoFromStat(name, new(FileInfo), &stat, &stat), nil
 }
 
-// Readdir reads the contents of the directory associated with file and
-// returns an array of up to count FileInfo structures, as would be returned
-// by Stat, in directory order.  Subsequent calls on the same file will yield
-// further FileInfos.
-// A negative count means to read until EOF.
-// Readdir returns the array and an Error, if any.
-func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
-	dirname := file.name
-	if dirname == "" {
-		dirname = "."
-	}
-	dirname += "/"
-	names, err1 := file.Readdirnames(count)
-	if err1 != nil {
-		return nil, err1
-	}
-	fi = make([]FileInfo, len(names))
-	for i, filename := range names {
-		fip, err := Lstat(dirname + filename)
-		if fip == nil || err != nil {
-			fi[i].Name = filename // rest is already zeroed out
-		} else {
-			fi[i] = *fip
-		}
-	}
-	return
-}
-
 // Chdir changes the current working directory to the named directory.
 func Chdir(dir string) Error {
 	if e := syscall.Chdir(dir); e != 0 {
diff --git a/src/pkg/os/file_mingw.go b/src/pkg/os/file_mingw.go
new file mode 100644
index 0000000..b9ba6a9
--- /dev/null
+++ b/src/pkg/os/file_mingw.go
@@ -0,0 +1,131 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The os package provides a platform-independent interface to operating
+// system functionality.  The design is Unix-like.
+package os
+
+import (
+	"runtime"
+	"syscall"
+)
+
+// Auxiliary information if the File describes a directory
+type dirInfo struct {
+	stat         syscall.Stat_t
+	usefirststat bool
+}
+
+func (file *File) isdir() bool { return file != nil && file.dirinfo != nil }
+
+func openFile(name string, flag int, perm int) (file *File, err Error) {
+	r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, perm)
+	if e != 0 {
+		return nil, &PathError{"open", name, Errno(e)}
+	}
+
+	// There's a race here with fork/exec, which we are
+	// content to live with.  See ../syscall/exec.go
+	if syscall.O_CLOEXEC == 0 { // O_CLOEXEC not supported
+		syscall.CloseOnExec(r)
+	}
+
+	return NewFile(r, name), nil
+}
+
+func openDir(name string) (file *File, err Error) {
+	d := new(dirInfo)
+	r, e := syscall.FindFirstFile(syscall.StringToUTF16Ptr(name+"\\*"), &d.stat.Windata)
+	if e != 0 {
+		return nil, &PathError{"open", name, Errno(e)}
+	}
+	f := NewFile(int(r), name)
+	d.usefirststat = true
+	f.dirinfo = d
+	return f, nil
+}
+
+// Open opens the named file with specified flag (O_RDONLY etc.) and perm, (0666 etc.)
+// if applicable.  If successful, methods on the returned File can be used for I/O.
+// It returns the File and an Error, if any.
+func Open(name string, flag int, perm int) (file *File, err Error) {
+	// TODO(brainman): not sure about my logic of assuming it is dir first, then fall back to file
+	r, e := openDir(name)
+	if e == nil {
+		return r, nil
+	}
+	r, e = openFile(name, flag|syscall.O_CLOEXEC, perm)
+	if e == nil {
+		return r, nil
+	}
+	return nil, e
+}
+
+// Close closes the File, rendering it unusable for I/O.
+// It returns an Error, if any.
+func (file *File) Close() Error {
+	if file == nil || file.fd < 0 {
+		return EINVAL
+	}
+	var e int
+	if file.isdir() {
+		_, e = syscall.FindClose(int32(file.fd))
+	} else {
+		_, e = syscall.CloseHandle(int32(file.fd))
+	}
+	var err Error
+	if e != 0 {
+		err = &PathError{"close", file.name, Errno(e)}
+	}
+	file.fd = -1 // so it can't be closed again
+
+	// no need for a finalizer anymore
+	runtime.SetFinalizer(file, nil)
+	return err
+}
+
+// Readdir reads the contents of the directory associated with file and
+// returns an array of up to count FileInfo structures, as would be returned
+// by Stat, in directory order.  Subsequent calls on the same file will yield
+// further FileInfos.
+// A negative count means to read until EOF.
+// Readdir returns the array and an Error, if any.
+func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
+	di := file.dirinfo
+	size := count
+	if size < 0 {
+		size = 100
+	}
+	fi = make([]FileInfo, 0, size) // Empty with room to grow.
+	for count != 0 {
+		if di.usefirststat {
+			di.usefirststat = false
+		} else {
+			_, e := syscall.FindNextFile(int32(file.fd), &di.stat.Windata)
+			if e != 0 {
+				if e == syscall.ERROR_NO_MORE_FILES {
+					break
+				} else {
+					return nil, &PathError{"FindNextFile", file.name, Errno(e)}
+				}
+			}
+		}
+		var f FileInfo
+		fileInfoFromStat("", &f, &di.stat, &di.stat)
+		if f.Name == "." || f.Name == ".." { // Useless names
+			continue
+		}
+		count--
+		if len(fi) == cap(fi) {
+			nfi := make([]FileInfo, len(fi), 2*len(fi))
+			for i := 0; i < len(fi); i++ {
+				nfi[i] = fi[i]
+			}
+			fi = nfi
+		}
+		fi = fi[0 : len(fi)+1]
+		fi[len(fi)-1] = f
+	}
+	return fi, nil
+}
diff --git a/src/pkg/os/file_unix.go b/src/pkg/os/file_unix.go
new file mode 100644
index 0000000..84ca480
--- /dev/null
+++ b/src/pkg/os/file_unix.go
@@ -0,0 +1,82 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// The os package provides a platform-independent interface to operating
+// system functionality.  The design is Unix-like.
+package os
+
+import (
+	"runtime"
+	"syscall"
+)
+
+// Auxiliary information if the File describes a directory
+type dirInfo struct {
+	buf  []byte // buffer for directory I/O
+	nbuf int    // length of buf; return value from Getdirentries
+	bufp int    // location of next record in buf.
+}
+
+// Open opens the named file with specified flag (O_RDONLY etc.) and perm, (0666 etc.)
+// if applicable.  If successful, methods on the returned File can be used for I/O.
+// It returns the File and an Error, if any.
+func Open(name string, flag int, perm int) (file *File, err Error) {
+	r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, perm)
+	if e != 0 {
+		return nil, &PathError{"open", name, Errno(e)}
+	}
+
+	// There's a race here with fork/exec, which we are
+	// content to live with.  See ../syscall/exec.go
+	if syscall.O_CLOEXEC == 0 { // O_CLOEXEC not supported
+		syscall.CloseOnExec(r)
+	}
+
+	return NewFile(r, name), nil
+}
+
+// Close closes the File, rendering it unusable for I/O.
+// It returns an Error, if any.
+func (file *File) Close() Error {
+	if file == nil || file.fd < 0 {
+		return EINVAL
+	}
+	var err Error
+	if e := syscall.Close(file.fd); e != 0 {
+		err = &PathError{"close", file.name, Errno(e)}
+	}
+	file.fd = -1 // so it can't be closed again
+
+	// no need for a finalizer anymore
+	runtime.SetFinalizer(file, nil)
+	return err
+}
+
+// Readdir reads the contents of the directory associated with file and
+// returns an array of up to count FileInfo structures, as would be returned
+// by Stat, in directory order.  Subsequent calls on the same file will yield
+// further FileInfos.
+// A negative count means to read until EOF.
+// Readdir returns the array and an Error, if any.
+func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
+	dirname := file.name
+	if dirname == "" {
+		dirname = "."
+	}
+	dirname += "/"
+	names, err1 := file.Readdirnames(count)
+	if err1 != nil {
+		return nil, err1
+	}
+	fi = make([]FileInfo, len(names))
+	for i, filename := range names {
+		fip, err := Lstat(dirname + filename)
+		if fip == nil || err != nil {
+			fi[i].Name = filename // rest is already zeroed out
+		} else {
+			fi[i] = *fip
+		}
+	}
+	return
+}
diff --git a/src/pkg/os/stat_mingw.go b/src/pkg/os/stat_mingw.go
index 8e2c73c..b22843a 100644
--- a/src/pkg/os/stat_mingw.go
+++ b/src/pkg/os/stat_mingw.go
@@ -6,10 +6,25 @@
 
 import "syscall"
 
-func isSymlink(stat *syscall.Stat_t) bool {
-	panic("windows isSymlink not implemented")
-}
-
 func fileInfoFromStat(name string, fi *FileInfo, lstat, stat *syscall.Stat_t) *FileInfo {
-	panic("windows fileInfoFromStat not implemented")
+	fi.Mode = 0
+	if stat.Windata.FileAttributes == syscall.FILE_ATTRIBUTE_DIRECTORY {
+		fi.Mode = fi.Mode | syscall.S_IFDIR
+	}
+	if stat.Windata.FileAttributes == syscall.FILE_ATTRIBUTE_NORMAL {
+		fi.Mode = fi.Mode | syscall.S_IFREG
+	}
+	if stat.Windata.FileAttributes == syscall.FILE_ATTRIBUTE_READONLY {
+		fi.Mode = fi.Mode | 0444
+	} else {
+		fi.Mode = fi.Mode | 0666
+	}
+	fi.Size = uint64(stat.Windata.FileSizeHigh)<<32 + uint64(stat.Windata.FileSizeLow)
+	fi.Name = string(syscall.UTF16ToString(stat.Windata.FileName[0:]))
+	fi.FollowedSymlink = false
+	// TODO(brainman): use CreationTime LastAccessTime LastWriteTime to prime following Dir fields
+	fi.Atime_ns = 0
+	fi.Mtime_ns = 0
+	fi.Ctime_ns = 0
+	return fi
 }
diff --git a/src/pkg/syscall/syscall_mingw.go b/src/pkg/syscall/syscall_mingw.go
index 97ddc6d..c3f8b9f 100644
--- a/src/pkg/syscall/syscall_mingw.go
+++ b/src/pkg/syscall/syscall_mingw.go
@@ -57,8 +57,11 @@
 // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
 // with a terminating NUL removed.
 func UTF16ToString(s []uint16) string {
-	if n := len(s); n > 0 && s[n-1] == 0 {
-		s = s[0 : n-1]
+	for i, v := range s {
+		if v == 0 {
+			s = s[0:i]
+			break
+		}
 	}
 	return string(utf16.Decode(s))
 }
@@ -105,6 +108,9 @@
 //sys	SetFilePointer(handle int32, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, errno int) [failretval=0xffffffff]
 //sys	CloseHandle(handle int32) (ok bool, errno int)
 //sys	GetStdHandle(stdhandle int32) (handle int32, errno int) [failretval=-1]
+//sys	FindFirstFile(name *uint16, data *Win32finddata) (handle int32, errno int) [failretval=-1] = FindFirstFileW
+//sys	FindNextFile(handle int32, data *Win32finddata) (ok bool, errno int) = FindNextFileW
+//sys	FindClose(handle int32) (ok bool, errno int)
 
 // syscall interface implementation for other packages
 
@@ -117,7 +123,7 @@
 	if err != 0 {
 		return "error " + str(errno) + " (FormatMessage failed with err=" + str(err) + ")"
 	}
-	return UTF16ToString(b[0 : n-1])
+	return string(utf16.Decode(b[0 : n-1]))
 }
 
 func Exit(code int) { ExitProcess(uint32(code)) }
@@ -253,20 +259,31 @@
 	return int(r)
 }
 
+func Stat(path string, stat *Stat_t) (errno int) {
+	h, e := FindFirstFile(StringToUTF16Ptr(path), &stat.Windata)
+	if e != 0 {
+		return e
+	}
+	defer FindClose(h)
+	stat.Mode = 0
+	return 0
+}
+
+func Lstat(path string, stat *Stat_t) (errno int) {
+	// no links on windows, just call Stat
+	return Stat(path, stat)
+}
+
 // TODO(brainman): fix all needed for os
 
 const (
 	SIGTRAP = 5
 )
 
-func Getdents(fd int, buf []byte) (n int, errno int) { return 0, EMINGW }
-
 func Getpid() (pid int)   { return -1 }
 func Getppid() (ppid int) { return -1 }
 
 func Mkdir(path string, mode int) (errno int)             { return EMINGW }
-func Lstat(path string, stat *Stat_t) (errno int)         { return EMINGW }
-func Stat(path string, stat *Stat_t) (errno int)          { return EMINGW }
 func Fstat(fd int, stat *Stat_t) (errno int)              { return EMINGW }
 func Chdir(path string) (errno int)                       { return EMINGW }
 func Fchdir(fd int) (errno int)                           { return EMINGW }
diff --git a/src/pkg/syscall/syscall_mingw_386.go b/src/pkg/syscall/syscall_mingw_386.go
index 0368620..1ce025b 100644
--- a/src/pkg/syscall/syscall_mingw_386.go
+++ b/src/pkg/syscall/syscall_mingw_386.go
@@ -4,6 +4,4 @@
 
 package syscall
 
-// TODO(brainman): check Getpagesize
-
 func Getpagesize() int { return 4096 }
diff --git a/src/pkg/syscall/zerrors_mingw_386.go b/src/pkg/syscall/zerrors_mingw_386.go
index d99aa22..707e9b8 100644
--- a/src/pkg/syscall/zerrors_mingw_386.go
+++ b/src/pkg/syscall/zerrors_mingw_386.go
@@ -7,6 +7,7 @@
 
 const (
 	ERROR_FILE_NOT_FOUND      = 2
+	ERROR_NO_MORE_FILES       = 18
 	ERROR_INSUFFICIENT_BUFFER = 122
 	ERROR_MOD_NOT_FOUND       = 126
 	ERROR_PROC_NOT_FOUND      = 127
diff --git a/src/pkg/syscall/zsyscall_mingw_386.go b/src/pkg/syscall/zsyscall_mingw_386.go
index c01f40e..185180a 100644
--- a/src/pkg/syscall/zsyscall_mingw_386.go
+++ b/src/pkg/syscall/zsyscall_mingw_386.go
@@ -20,6 +20,9 @@
 	procSetFilePointer = getSysProcAddr(modKERNEL32, "SetFilePointer")
 	procCloseHandle    = getSysProcAddr(modKERNEL32, "CloseHandle")
 	procGetStdHandle   = getSysProcAddr(modKERNEL32, "GetStdHandle")
+	procFindFirstFileW = getSysProcAddr(modKERNEL32, "FindFirstFileW")
+	procFindNextFileW  = getSysProcAddr(modKERNEL32, "FindNextFileW")
+	procFindClose      = getSysProcAddr(modKERNEL32, "FindClose")
 )
 
 func GetLastError() (lasterrno int) {
@@ -165,3 +168,36 @@
 	}
 	return
 }
+
+func FindFirstFile(name *uint16, data *Win32finddata) (handle int32, errno int) {
+	r0, _, e1 := Syscall(procFindFirstFileW, uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(data)), 0)
+	handle = int32(r0)
+	if handle == -1 {
+		errno = int(e1)
+	} else {
+		errno = 0
+	}
+	return
+}
+
+func FindNextFile(handle int32, data *Win32finddata) (ok bool, errno int) {
+	r0, _, e1 := Syscall(procFindNextFileW, uintptr(handle), uintptr(unsafe.Pointer(data)), 0)
+	ok = bool(r0 != 0)
+	if !ok {
+		errno = int(e1)
+	} else {
+		errno = 0
+	}
+	return
+}
+
+func FindClose(handle int32) (ok bool, errno int) {
+	r0, _, e1 := Syscall(procFindClose, uintptr(handle), 0, 0)
+	ok = bool(r0 != 0)
+	if !ok {
+		errno = int(e1)
+	} else {
+		errno = 0
+	}
+	return
+}
diff --git a/src/pkg/syscall/ztypes_mingw_386.go b/src/pkg/syscall/ztypes_mingw_386.go
index 93364e4..c683c6e 100644
--- a/src/pkg/syscall/ztypes_mingw_386.go
+++ b/src/pkg/syscall/ztypes_mingw_386.go
@@ -78,6 +78,8 @@
 	FORMAT_MESSAGE_FROM_SYSTEM     = 4096
 	FORMAT_MESSAGE_ARGUMENT_ARRAY  = 8192
 	FORMAT_MESSAGE_MAX_WIDTH_MASK  = 255
+
+	MAX_PATH = 260
 )
 
 // Types
@@ -103,6 +105,29 @@
 	HEvent       *byte
 }
 
+type Filetime struct {
+	LowDateTime  uint32
+	HighDateTime uint32
+}
+
+type Win32finddata struct {
+	FileAttributes    uint32
+	CreationTime      Filetime
+	LastAccessTime    Filetime
+	LastWriteTime     Filetime
+	FileSizeHigh      uint32
+	FileSizeLow       uint32
+	Reserved0         uint32
+	Reserved1         uint32
+	FileName          [MAX_PATH - 1]uint16
+	AlternateFileName [13]uint16
+}
+
+type Stat_t struct {
+	Windata Win32finddata
+	Mode    uint32
+}
+
 // TODO(brainman): fix all needed for os
 
 const (
@@ -135,28 +160,3 @@
 	S_IWUSR    = 0x80
 	S_IXUSR    = 0x40
 )
-
-type Stat_t struct {
-	Dev       int64
-	Ino       uint32
-	Mode      uint32
-	Nlink     uint32
-	Uid       uint32
-	Gid       uint32
-	__padding int32
-	Rdev      int64
-	Size      int32
-	Blksize   int32
-	Blocks    int32
-	Atime     int32
-	Mtime     int32
-	Ctime     int32
-}
-
-type Dirent struct {
-	Ino    uint32
-	Off    int32
-	Reclen uint16
-	Name   [256]int8
-	Pad0   [2]byte
-}