diff --git a/src/main/java/org/dostalgia/ExecutableDetector.java b/src/main/java/org/dostalgia/ExecutableDetector.java
index f8f2fee..b6cf0b5 100644
--- a/src/main/java/org/dostalgia/ExecutableDetector.java
+++ b/src/main/java/org/dostalgia/ExecutableDetector.java
@@ -82,9 +82,9 @@ public class ExecutableDetector {
     }
 
     public String findSetup(Path dir) throws IOException {
-        record Candidate(int depth, long size, String path) {}
+        record Candidate(int depth, boolean isWindows, long size, String path) {}
         List<Candidate> candidates = new ArrayList<>();
-        List<String> patterns = List.of("setup", "install", "config", "custom");
+        List<String> patterns = List.of("setup", "setmain", "install", "config", "custom");
 
         Files.walkFileTree(dir, new SimpleFileVisitor<>() {
             @Override
@@ -95,8 +95,9 @@ public class ExecutableDetector {
                     return FileVisitResult.CONTINUE;
                 for (String pat : patterns) {
                     if (stem.equals(pat) || stem.startsWith(pat + ".") || stem.startsWith(pat + "-")) {
+                        boolean isWin = "windows".equals(platform.detect(f));
                         candidates.add(new Candidate(
-                            f.getNameCount() - dir.getNameCount(), a.size(), f.toString()));
+                            f.getNameCount() - dir.getNameCount(), isWin, a.size(), f.toString()));
                         break;
                     }
                 }
@@ -105,7 +106,10 @@ public class ExecutableDetector {
         });
 
         if (candidates.isEmpty()) return null;
-        candidates.sort(Comparator.comparingInt(Candidate::depth).thenComparingLong(Candidate::size));
+        candidates.sort(Comparator
+            .<Candidate, Integer>comparingInt(c -> c.isWindows() ? 1 : 0)  // prefer DOS over Windows
+            .thenComparingInt(Candidate::depth)
+            .thenComparingLong(Candidate::size));
         return candidates.getFirst().path();
     }
 
diff --git a/src/main/java/org/dostalgia/PlatformDetector.java b/src/main/java/org/dostalgia/PlatformDetector.java
index 9bf69be..4366dc6 100644
--- a/src/main/java/org/dostalgia/PlatformDetector.java
+++ b/src/main/java/org/dostalgia/PlatformDetector.java
@@ -30,7 +30,7 @@ public class PlatformDetector {
 
     /** Read enough PE header bytes from any InputStream (shared by Path and ZIP callers). */
     static byte[] readHeaderBytes(InputStream is) throws IOException {
-        byte[] buf = new byte[0x200];
+        byte[] buf = new byte[0x1000];
         int read = is.readNBytes(buf, 0, buf.length);
         return read < buf.length ? java.util.Arrays.copyOf(buf, read) : buf;
     }