Change the number of recently opened files that appear on the Office menu : Workbook Open « Editing « Microsoft Office Excel 2007 Tutorial

1. Microsoft Office Excel 2007 Tutorial
2. Editing
3. Workbook Open

Click the Office button. Then click Excel Options

Then click Advanced. 
           Then change the Number of documents in the Recent Documents list

Then click OK.

2.2.Workbook Open
	2.2.1.	Open a Workbook from the Excel Window
	2.2.2.	Open a Recently Opened Workbook
	2.2.3.	Pin/Unpin a workbook
	2.2.4.	Change the number of recently opened files that appear on the Office menu
	2.2.5.	Change the default file location of the Open dialog box