a58 is start cell


a130 is end cell

.
Ok .. then paste the following in A58 :

=IF(ISBLANK(B58)," ",COUNTA($B$58:B58))

Then follow the same instructions as before :

Once you have the formula in the cell, click on the cell and a small dot will appear
in the lower right hand corner of the cell. Hover your cursor over that tiny black
dot until the cursor becomes a cross symbol. While it remains the cross, double
click the dot. The formula should auto-fill all the cells in Col A that are adjacent
to a cell in Col B that has some data.

Be sure to delete the macro from the worksheet module.