diff --git a/src/main/java/com/dostalgia/GameService.java b/src/main/java/com/dostalgia/GameService.java
index 4e71286..a24addb 100644
--- a/src/main/java/com/dostalgia/GameService.java
+++ b/src/main/java/com/dostalgia/GameService.java
@@ -237,7 +237,7 @@ public class GameService {
         sb.append("[dos]\nxms=true\nems=true\numb=true\n\n");
         sb.append("[autoexec]\n@echo off\nmount c .\n");
         // Mount CD images as D:, E:, … so games can find their CD.
-        // Deduplicate by parent directory — prefer .bin over .cue.
+        // Deduplicate by parent directory — prefer data formats over descriptors.
         Set<String> seenDirs = new java.util.HashSet<>();
         char driveLetter = 'D';
         for (String img : cdImages) {
@@ -245,6 +245,17 @@ public class GameService {
             String parentDir = slashIdx >= 0 ? img.substring(0, slashIdx) : "";
             if (!seenDirs.add(parentDir)) continue;
             String imgLower = img.toLowerCase();
+            // Skip descriptor formats if a data format exists in the same directory
+            if (imgLower.endsWith(".cue") || imgLower.endsWith(".ccd")) {
+                boolean hasData = cdImages.stream().anyMatch(i -> {
+                    int is = i.lastIndexOf('/');
+                    String ip = is >= 0 ? i.substring(0, is) : "";
+                    String il = i.toLowerCase();
+                    return ip.equals(parentDir)
+                        && (il.endsWith(".img") || il.endsWith(".iso") || il.endsWith(".bin"));
+                });
+                if (hasData) continue;
+            }
             String flags = imgLower.endsWith(".bin") ? " -t cdrom -fs iso" : " -t cdrom";
             sb.append("imgmount ").append(driveLetter).append(" \"").append(img).append("\"").append(flags).append("\n");
             driveLetter++;
diff --git a/src/main/java/com/dostalgia/UploadResource.java b/src/main/java/com/dostalgia/UploadResource.java
index 4079015..b4490d1 100644
--- a/src/main/java/com/dostalgia/UploadResource.java
+++ b/src/main/java/com/dostalgia/UploadResource.java
@@ -580,6 +580,17 @@ public class UploadResource {
             String parentDir = slashIdx >= 0 ? img.substring(0, slashIdx) : "";
             if (!seenDirs.add(parentDir)) continue;
             String imgLower = img.toLowerCase();
+            // Skip descriptor formats if a data format exists in the same directory
+            if (imgLower.endsWith(".cue") || imgLower.endsWith(".ccd")) {
+                boolean hasData = cdImages.stream().anyMatch(i -> {
+                    int is = i.lastIndexOf('/');
+                    String ip = is >= 0 ? i.substring(0, is) : "";
+                    String il = i.toLowerCase();
+                    return ip.equals(parentDir)
+                        && (il.endsWith(".img") || il.endsWith(".iso") || il.endsWith(".bin"));
+                });
+                if (hasData) continue;
+            }
             String flags = imgLower.endsWith(".bin") ? " -t cdrom -fs iso" : " -t cdrom";
             sb.append("imgmount ").append(driveLetter).append(" \"").append(img).append("\"").append(flags).append("\n");
             driveLetter++;
@@ -638,9 +649,8 @@ public class UploadResource {
         sb.append("@echo off\n");
         sb.append("mount c .\n");
         // Mount CD images as D:, E:, … so games can find their CD.
-        // Deduplicate by parent directory — prefer .bin over .cue since
-        // .bin files sort first alphabetically and avoid .cue FILE path
-        // case-mismatch issues.
+        // Deduplicate by parent directory — prefer data formats (.img, .iso, .bin)
+        // over descriptor formats (.cue, .ccd) which can have FILE path case-mismatch.
         Set<String> seenDirs = new java.util.HashSet<>();
         char driveLetter = 'D';
         for (String img : cdImages) {
@@ -648,6 +658,17 @@ public class UploadResource {
             String parentDir = slashIdx >= 0 ? img.substring(0, slashIdx) : "";
             if (!seenDirs.add(parentDir)) continue; // already mounted from this dir
             String imgLower = img.toLowerCase();
+            // Skip descriptor formats if a data format exists in the same directory
+            if (imgLower.endsWith(".cue") || imgLower.endsWith(".ccd")) {
+                boolean hasData = cdImages.stream().anyMatch(i -> {
+                    int is = i.lastIndexOf('/');
+                    String ip = is >= 0 ? i.substring(0, is) : "";
+                    String il = i.toLowerCase();
+                    return ip.equals(parentDir)
+                        && (il.endsWith(".img") || il.endsWith(".iso") || il.endsWith(".bin"));
+                });
+                if (hasData) continue; // data file will be mounted instead (lower in list)
+            }
             String flags = imgLower.endsWith(".bin") ? " -t cdrom -fs iso" : " -t cdrom";
             sb.append("imgmount ").append(driveLetter).append(" \"").append(img).append("\"").append(flags).append("\n");
             driveLetter++;