Index: main/core/src/main/java/hudson/util/FormFieldValidator.java
===================================================================
--- main/core/src/main/java/hudson/util/FormFieldValidator.java	(revision 11987)
+++ main/core/src/main/java/hudson/util/FormFieldValidator.java	(working copy)
@@ -444,8 +444,19 @@
             } else {
                 // look in PATH
                 String path = EnvVars.masterEnvVars.get("PATH");
+                String tokenizedPath = "";
+                String delimiter = null;
                 if(path!=null) {
-                    for (String _dir : Util.tokenize(path,File.pathSeparator)) {
+                    for (String _dir : Util.tokenize(path.replace("\\", "\\\\"),File.pathSeparator)) {
+                        if (delimiter == null) {
+                          delimiter = ", ";
+                        }
+                        else {
+                          tokenizedPath += delimiter;
+                        }
+
+                        tokenizedPath += _dir.replace('\\', '/');
+                        
                         File dir = new File(_dir);
 
                         File f = new File(dir,exe);
@@ -460,10 +471,15 @@
                             return;
                         }
                     }
+                    
+                    tokenizedPath += ".";
                 }
+                else {
+                  tokenizedPath = "unavailable.";
+                }
 
                 // didn't find it
-                error("There's no such executable "+exe+" in PATH:"+path);
+                error("There's no such executable "+exe+" in PATH: "+tokenizedPath);
             }
         }