The Recent Files Comparisons window shows a list of the last 50 pairs of files recently compared.  You can use it to select a pair of files to compare on the Start Page when in Compare Files mode.  Click the Recent Comparisons link in the upper right corner of the Start Page when in Compare File mode to bring up this window.

 

Remove a pair of files from list

 

To remove a pair of files from the list, click on the red remove image  which appears on the right edge of the row when the mouse pointer hovers over it.

 

 

Clear the entire list

 

To remove all file pairs from the list, click the Clear List link at the bottom right of the window.