Undo and Redo
In Creo Elements/Direct Drafting, you can undo mistakes with 
Undo or 
Redo:
Undo or Redo:• On the Quick Access Toolbar, click to undo an operation or press CTRL+Z.
to undo an operation or press CTRL+Z.• On the Quick Access Toolbar, click to redo an operation (after you have clicked Undo) or press CTRL+Y.
to redo an operation (after you have clicked Undo) or press CTRL+Y.Each time you click Undo or Redo, you will undo or redo all the changes that were created by the last button you clicked.
Undo or Redo, you will undo or redo all the changes that were created by the last button you clicked.You can set a limit on the number of steps to keep in the Undo history in the System dialog box.
Undo history in the System dialog box.1. Click > > 
System.
System.The System dialog box opens.
2. Click Environment.
3. In the Undo area, click one of the following:
◦ Click Unlimited to allow unlimited number of steps for Undo.
Undo.◦ Click Max steps and type the maximum number of steps allowed in the Undo history.
Undo history.