How do I make the verticle scroll bar full size post row delete?

[Guest]

I need to resize my verticle scroll bar in excell to match my remaining data.
This seems like it should be a simple task. example: I have 100 rows of
data. I use a subtotal function to delete duplicates, which doubles the
amount of rows, and shrinks my scroll bar. After I remove the subtotals, my
scroll bar still takes me down 200 rows while I may only have 50 rows of data
now.

HELP!

 

[Dave Peterson]

Debra Dalgleish shows techniques to reset that last used cell:
http://contextures.com/xlfaqApp.html#Unused