Index: base/setup/usetup/errorcode.h
===================================================================
--- base/setup/usetup/errorcode.h	(Revision 55348)
+++ base/setup/usetup/errorcode.h	(Arbeitskopie)
@@ -66,6 +66,7 @@
     ERROR_ADDING_KBLAYOUTS,
     ERROR_UPDATE_GEOID,
     ERROR_INSUFFICIENT_DISKSPACE,
+    ERROR_DIRECTORY_NAME,
 
     ERROR_LAST_ERROR_CODE
 }ERROR_NUMBER;
Index: base/setup/usetup/lang/de-DE.h
===================================================================
--- base/setup/usetup/lang/de-DE.h	(Revision 55348)
+++ base/setup/usetup/lang/de-DE.h	(Arbeitskopie)
@@ -1486,6 +1486,11 @@
     {
         //ERROR_INSUFFICIENT_DISKSPACE,
         "Nicht genug Speicherplatz auf der gew„hlten Partition vorhanden.\n"
+        "  * Eine beliebige Taste zum Fortsetzen drcken."
+    },
+    {
+        //ERROR_DIRECTORY_NAME,
+        "Unzul„ssiger Verzeichnisname.\n"
         "  * Eine beliebige Taste zum Fortsetzen drcken.",
         NULL
     },
Index: base/setup/usetup/lang/en-US.h
===================================================================
--- base/setup/usetup/lang/en-US.h	(Revision 55348)
+++ base/setup/usetup/lang/en-US.h	(Arbeitskopie)
@@ -1485,6 +1485,11 @@
     {
         //ERROR_INSUFFICIENT_DISKSPACE,
         "Not enough free space in the selected partition.\n"
+        "  * Press any key to continue."
+    },
+    {
+        //ERROR_DIRECTORY_NAME,
+        "invalid directory name.\n"
         "  * Press any key to continue.",
         NULL
     },
Index: base/setup/usetup/filesup.c
===================================================================
--- base/setup/usetup/filesup.c	(Revision 55348)
+++ base/setup/usetup/filesup.c	(Arbeitskopie)
@@ -392,4 +392,23 @@
   return(TRUE);
 }
 
+BOOLEAN
+IsValidPath(PWCHAR InstallDir, ULONG Length)
+{
+   int i;
+
+   /* TODO: Add check for 8.3 too
+
+   /* Check for Whitespaces */
+   for(i=0;i<=Length;i++)
+   {
+      if(isspace(InstallDir[i]))
+      {
+         return(FALSE);
+      }
+   }
+
+   return(TRUE);
+}
+
 /* EOF */
Index: base/setup/usetup/filesup.h
===================================================================
--- base/setup/usetup/filesup.h	(Revision 55348)
+++ base/setup/usetup/filesup.h	(Arbeitskopie)
@@ -42,4 +42,8 @@
 DoesFileExist(PWSTR PathName,
 	      PWSTR FileName);
 
+BOOLEAN
+IsValidPath(PWCHAR InstallDir,
+            ULONG Length);
+
 /* EOF */
Index: base/setup/usetup/interface/usetup.c
===================================================================
--- base/setup/usetup/interface/usetup.c	(Revision 55348)
+++ base/setup/usetup/interface/usetup.c	(Arbeitskopie)
@@ -2677,6 +2677,11 @@
         }
         else if (Ir->Event.KeyEvent.uChar.AsciiChar == 0x0D) /* ENTER */
         {
+            if(!IsValidPath(InstallDir, Length))
+            {
+                MUIDisplayError(ERROR_DIRECTORY_NAME, Ir, POPUP_WAIT_ENTER);
+                return INSTALL_DIRECTORY_PAGE;
+            }
             return InstallDirectoryPage1(InstallDir,
                                          DiskEntry,
                                          PartEntry,