diff --git a/src/main/java/com/metaweb/gridworks/ProjectManager.java b/src/main/java/com/metaweb/gridworks/ProjectManager.java
index a714c1514..50e1e5308 100644
--- a/src/main/java/com/metaweb/gridworks/ProjectManager.java
+++ b/src/main/java/com/metaweb/gridworks/ProjectManager.java
@@ -82,7 +82,7 @@ public class ProjectManager {
                 // it's not elegant but it's the safest bet.
                 
                 DataPath localDataPath = JDataPathSystem.getLocalSystem().getLocalDataPath("Gridworks");
-                File data = new File(localDataPath.getPath());
+                File data = new File(fixWindowsUnicodePath(localDataPath.getPath()));
                 data.mkdirs();
                 return data;
             } catch (Error e) {
@@ -139,6 +139,31 @@ public class ProjectManager {
         }
     }
     
+    /**
+     * For Windows file paths that contain user IDs with non ASCII characters,
+     * those characters might get replaced with ?. We need to use the environment
+     * APPDATA value to substitute back the original user ID.
+     */
+    static protected String fixWindowsUnicodePath(String path) {
+    	int q = path.indexOf('?');
+    	if (q < 0) {
+    		return path;
+    	}
+    	int pathSep = path.indexOf(File.separatorChar, q);
+    	
+    	String goodPath = System.getenv("APPDATA");
+    	if (goodPath == null || goodPath.length() == 0) {
+            goodPath = System.getenv("USERPROFILE");
+            if (!goodPath.endsWith(File.separator)) {
+            	goodPath = goodPath + File.separator;
+            }
+    	}
+    	
+    	int goodPathSep = goodPath.indexOf(File.separatorChar, q);
+    	
+    	return path.substring(0, q) + goodPath.substring(q, goodPathSep) + path.substring(pathSep);
+    }
+    
     private ProjectManager(File dir) {
         _workspaceDir = dir;
         _workspaceDir.mkdirs();