In Excel (2007/2010) you can auto increment by dragging cell corner. But some how excel drag was not working in newer installation of excel on my machine. After 10-15 minutes of struggle I was able to fix that.
Did you also not able to auto-increment by drag cells in excel?
I am providing step by step process to enable auto increment by dragging cell corner in excel (2007/2010). Its quick and take less than 10 seconds.
Step 1:
For excel 2007 click on office icon on top left 
For excel 2010 click on “File” on top left 
Step 2:
For excel 2007 click on the Excel Options
For excel 2010 click on the options
then go to “Advance” for excel 2007/2010.
Under “Edit Options” there is a check box named “Enable fill handle and cell drag-and-drop”. Select the check box to enable the auto increment.
That’s it!!! now you have enabled excel (2007/2010) auto increment drag cell corner.
Hope this help!!!