ONLY the totally blank rows had been selected! The result was a sheet of empty cells with 0s in column D. Then I used the FILTER command on Column D to only show the rows that equalled 0. So, my D column had a stack of 3s,2s,1s & 0s. The formula went =COUNTA(A1:C1) and then copied it down thru several thousand rows of data. I created a fourth column in which I used the COUNTA function. The PROBLEM was that selecting BLANK cells would DELETE ENTIRE ROWS that had data in other columns. Only SOME of the rows (1,242 in this case) were blank all the way across. Sometimes a row in column two was blank, but the cell beside it in column three had data. The remaining two columns had random data at various rows all the way down. The first column had title lines every five or six rows. "Blank rows deletion" is awkward by most methods. When they vanish, turn the Filter function off and all other data will reappear. Then as described previously, with the Filter function still active, highlight the rows from 147533 to 448140 that are containing those selected row numbers (by clicking/dragging down the left ruler margin OR clicking top one and shift-clicking last one), and DELETE them.
You should then see only rows that have zero data in them. Then select the Filter function (Data tab, Filter), click on the little pull-down triangle, and delete all the checkmark choices except the one beside the "0" choice (OR the "Blanks" choice, if visible). Then click on the "U" letter at the top of the column (in the ruler margin) to highlight the entire column. You should get a column of numbers, SOME of which will be zeroes. Your first step in the extra column (which should be "U" column for the filtering), the formula in U147533 should read (judging from your supplied data) =COUNTA(A147533:T147533) and then COPY that down to row 448140. What YOU would find is that once you've got a fixed-structure data set going, you'll know exactly how the procedure works and could just record steps into a macro of your own, just for the speed factor.)
(Mind you, at your first query, I envisioned a macro that would have to work in all environments. Oh, and make a backup copy, of course, just in case Undo fails or something while trying it out. A quickly-cleaned-up database will look more impressive than watching how it got that way, especially if you're just learning how. Re the folks you're doing the work for, just bring them the results they probably don't care "how", they just wanna know "what". Once you see it work the first time, you'll feel a lot more comfortable with it, and you'll definitely be wiser in the operation of the Filter function. Maybe try displaying steps side-by-side with the work you're doing (or print the steps out, then follow along). Really, the whole operation takes less than two minutes if you read over the instructions step by step. It would take about ten times longer to write such a macro (which would have to auto-calc total columns, total vertical fill in ALL columns, then calc which column to do the counts in, then execute the operation, etc.) than to just do the steps. Easy deploying in your enterprise or organization.