Index: /trunk/src/VBox/ValidationKit/testmanager/core/testboxcontroller.py
===================================================================
--- /trunk/src/VBox/ValidationKit/testmanager/core/testboxcontroller.py	(revision 61317)
+++ /trunk/src/VBox/ValidationKit/testmanager/core/testboxcontroller.py	(revision 61318)
@@ -395,5 +395,8 @@
         # Update the row in TestBoxes if something changed.
         #
-        cPctScratchDiff = (cMbScratch - oTestBox.cMbScratch) * 100 / oTestBox.cMbScratch;
+        if oTestBox.cMbScratch != 0:
+            cPctScratchDiff = (cMbScratch - oTestBox.cMbScratch) * 100 / oTestBox.cMbScratch;
+        else:
+            cPctScratchDiff = 100;
 
         # pylint: disable=R0916