diff --git a/.gitignore b/.gitignore
index 0fc978d..3e32be2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,4 +24,5 @@ go.work
 bin/
 *.dd
 *.zip
-!internal/testdata/*
+!internal/testdata/windows.zip
+!internal/testdata/windows.dd.zip
diff --git a/internal/sys/sys_test.go b/internal/sys/sys_test.go
index 8ea3dad..4bb3619 100644
--- a/internal/sys/sys_test.go
+++ b/internal/sys/sys_test.go
@@ -7,7 +7,7 @@ import (
 )
 
 func TestCall(t *testing.T) {
-	t.Run("Test layered call", func(t *testing.T) {
+	t.Run("Test call", func(t *testing.T) {
 		stdout := new(strings.Builder)
 		stderr := new(strings.Builder)
 
diff --git a/internal/testdata/windows.dd.zip b/internal/testdata/windows.dd.zip
new file mode 100644
index 0000000..c0a1e42
Binary files /dev/null and b/internal/testdata/windows.dd.zip differ
diff --git a/internal/zip/zip_test.go b/internal/zip/zip_test.go
index 6c8e7ef..281effd 100644
--- a/internal/zip/zip_test.go
+++ b/internal/zip/zip_test.go
@@ -1,2 +1,43 @@
 // Zip archive implementation tests.
 package zip
+
+import (
+	"os"
+	"path/filepath"
+	"slices"
+	"testing"
+
+	"github.com/cuhsat/fact/internal/test"
+)
+
+func TestIndex(t *testing.T) {
+	t.Run("Test index", func(t *testing.T) {
+		idx, err := Index(test.Testdata("windows.zip"))
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if !slices.Contains(idx, "Users/Test/NTUSER.DAT") {
+			t.Fatal("file not found")
+		}
+	})
+}
+
+func TestUnzip(t *testing.T) {
+	t.Run("Test unzip", func(t *testing.T) {
+		tmp, _ := os.MkdirTemp(os.TempDir(), "zip")
+
+		err := Unzip(test.Testdata("windows.zip"), tmp)
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		_, err = os.Stat(filepath.Join(tmp, "Windows"))
+
+		if os.IsNotExist(err) {
+			t.Fatal("folder not found")
+		}
+	})
+}
diff --git a/pkg/fmount/dd/dd.go b/pkg/fmount/dd/dd.go
index c3be72e..397f7a5 100644
--- a/pkg/fmount/dd/dd.go
+++ b/pkg/fmount/dd/dd.go
@@ -24,9 +24,7 @@ func Is(img string) (is bool, err error) {
 
 func Mount(img, dir string, so bool) (sysroot string, err error) {
 	if len(dir) == 0 {
-		b := filepath.Base(img)
-
-		dir = strings.TrimSuffix(b, filepath.Ext(b))
+		dir = baseFile(img)
 	}
 
 	if err = os.MkdirAll(dir, mode); err != nil {
@@ -151,6 +149,12 @@ func Unmount(img string) (err error) {
 	return
 }
 
+func baseFile(name string) string {
+	b := filepath.Base(name)
+
+	return strings.TrimSuffix(b, filepath.Ext(b))
+}
+
 func detectMagic(name string) (has bool, err error) {
 	f, err := os.Open(name)
 
diff --git a/pkg/fmount/dd/dd_test.go b/pkg/fmount/dd/dd_test.go
index 1dc6bda..6cbdaa8 100644
--- a/pkg/fmount/dd/dd_test.go
+++ b/pkg/fmount/dd/dd_test.go
@@ -1,2 +1,53 @@
 // DD implementation tests.
 package dd
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/cuhsat/fact/internal/test"
+	"github.com/cuhsat/fact/internal/zip"
+)
+
+func TestDD(t *testing.T) {
+	cases := []struct {
+		name, file string
+	}{
+		{
+			name: "Test mount for Windows",
+			file: test.Testdata("windows.dd.zip"),
+		},
+	}
+
+	for _, tt := range cases {
+		tmp, _ := os.MkdirTemp(os.TempDir(), "dd")
+		mnt, _ := os.MkdirTemp(os.TempDir(), "dd-mnt")
+
+		err := zip.Unzip(tt.file, tmp)
+
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		t.Run(tt.name, func(t *testing.T) {
+			img := filepath.Join(tmp, baseFile(tt.file))
+
+			p, err := Mount(img, mnt, true)
+
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if p != filepath.Join(mnt, "p1") {
+				t.Fatal("sysroot unexpected", p)
+			}
+
+			err = Unmount(img)
+
+			if err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}
diff --git a/pkg/fmount/fmount.go b/pkg/fmount/fmount.go
index f3f0720..0aa3776 100644
--- a/pkg/fmount/fmount.go
+++ b/pkg/fmount/fmount.go
@@ -28,12 +28,6 @@ func DetectType(img, t string) (string, error) {
 }
 
 func Extract(img string) (p string, err error) {
-	dir, err := os.Getwd()
-
-	if err != nil {
-		return
-	}
-
 	i, err := zip.Index(img)
 
 	if err != nil {
@@ -45,11 +39,18 @@ func Extract(img string) (p string, err error) {
 		return
 	}
 
-	if err = zip.Unzip(img, dir); err != nil {
+	dir := filepath.Dir(img)
+
+	p = path.Join(dir, i[0])
+
+	if _, err = os.Stat(p); !os.IsNotExist(err) {
+		err = errors.New("file already exists")
 		return
 	}
 
-	p = path.Join(dir, i[0])
+	if err = zip.Unzip(img, dir); err != nil {
+		return
+	}
 
 	return
 }