Index: base/setup/usetup/interface/usetup.c
===================================================================
--- base/setup/usetup/interface/usetup.c	(revision 74511)
+++ base/setup/usetup/interface/usetup.c	(working copy)
@@ -27,6 +27,7 @@
  */
 
 #include <usetup.h>
+#include <math.h>
 
 #include "bootsup.h"
 #include "chkdsk.h"
@@ -1755,9 +1756,9 @@
 }
 
 
-#define PARTITION_SIZE_INPUT_FIELD_LENGTH 6
-/* Restriction for MaxSize: pow(10, PARTITION_SIZE_INPUT_FIELD_LENGTH)-1 */
-#define PARTITION_MAXSIZE 999999
+#define PARTITION_SIZE_INPUT_FIELD_LENGTH 9
+/* Restriction for MaxSize: pow(10, (PARTITION_SIZE_INPUT_FIELD_LENGTH - 1)) - 1 */
+#define PARTITION_MAXSIZE (pow(10, (PARTITION_SIZE_INPUT_FIELD_LENGTH - 1)) - 1)
 
 static VOID
 ShowPartitionSizeInputBox(SHORT Left,
@@ -1853,7 +1854,7 @@
                                    PartitionSizeBuffer);
         }
         else if ((Ir.Event.KeyEvent.uChar.AsciiChar != 0x00) &&
-                 (Index < PARTITION_SIZE_INPUT_FIELD_LENGTH))
+                 (Index < PARTITION_SIZE_INPUT_FIELD_LENGTH - 1))
         {
             ch = (WCHAR)Ir.Event.KeyEvent.uChar.AsciiChar;