diff --git a/controllers/path_handler.py b/controllers/path_handler.py
index 4b50837..60b5fda 100644
--- a/controllers/path_handler.py
+++ b/controllers/path_handler.py
@@ -9,4 +9,13 @@ def fix_windows_path(dos_path: str, encoding=None):
             return u"\\\\?\\UNC\\" + path[2:]
         return u"\\\\?\\" + path
     else:
-        return dos_path
\ No newline at end of file
+        return dos_path
+
+def windows_join_path(og_path: str, join: str):
+    if os.name == 'nt':
+        final_path = og_path
+        for dir in join.split('/'):
+            final_path = os.path.join(final_path, dir)
+        return final_path
+    else:
+        return os.path.join(og_path, join)
\ No newline at end of file
diff --git a/gui/main_window.py b/gui/main_window.py
index 876fcbc..09b5288 100644
--- a/gui/main_window.py
+++ b/gui/main_window.py
@@ -20,7 +20,7 @@ from tweaks.tweaks import tweaks
 from tweaks.custom_gestalt_tweaks import CustomGestaltTweaks, ValueTypeStrings
 from tweaks.daemons_tweak import Daemon
 
-App_Version = "5.1"
+App_Version = "5.1.1"
 App_Build = 0
 
 class Page(Enum):
diff --git a/tweaks/posterboard_tweak.py b/tweaks/posterboard_tweak.py
index db4d834..d0a8a4f 100644
--- a/tweaks/posterboard_tweak.py
+++ b/tweaks/posterboard_tweak.py
@@ -11,6 +11,7 @@ from controllers.plist_handler import set_plist_value
 from controllers.files_handler import get_bundle_files
 from controllers import video_handler
 from controllers.aar.aar import wrap_in_aar
+from controllers.path_handler import fix_windows_path, windows_join_path
 
 class TendieFile:
     path: str
@@ -203,7 +204,7 @@ class PosterboardTweak(Tweak):
                 del video_contents
             to_override = ["input.segmentation/asset.resource/Adjusted.HEIC", "input.segmentation/asset.resource/proxy.heic", "output.layerStack/portrait-layer_background.HEIC"]
             for file in to_override:
-                with open(os.path.join(contents_path, file), "wb") as overriding:
+                with open(windows_join_path(contents_path, file), "wb") as overriding:
                     overriding.write(thumb_contents)
             del thumb_contents
 
@@ -211,9 +212,9 @@ class PosterboardTweak(Tweak):
         print(f"file: {self.videoFile}, looping: {self.loop_video}")
         if self.videoFile and self.loop_video:
             source_dir = get_bundle_files("files/posterboard/VideoCAML")
-            video_output_dir = os.path.join(output_dir, "descriptor/VideoCAML")
-            copytree(source_dir, video_output_dir, dirs_exist_ok=True)
-            contents_path = os.path.join(video_output_dir, "versions/1/contents/9183.Custom-810w-1080h@2x~ipad.wallpaper")
+            video_output_dir = windows_join_path(output_dir, "descriptor/VideoCAML")
+            copytree(fix_windows_path(source_dir), video_output_dir, dirs_exist_ok=True)
+            contents_path = windows_join_path(video_output_dir, "versions/1/contents/9183.Custom-810w-1080h@2x~ipad.wallpaper")
             if self.use_foreground:
                 # rename the foreground layer to background
                 bg_path = os.path.join(contents_path, "9183.Custom_Background-810w-1080h@2x~ipad.ca")