I use Inventoria as a non-business, hobbyist manner and do not need certain columns on the main screen.
Specifically, "Tax", "Price", and "Measure". You can minimize those columns but they reappear on next run.
Looking through the Registry (Windows 7) I found this key:
HKEY_CURRENT_USER\Software\NCH Software\Inventoria\MainDialogList
which contains string values (REG_SZ) "Col1" through "Col9", each containing numbers which are the column widths as so:
COL1 COL2 COL3 COL4 COL5 COL6 COL7 COL8 COL9
209 179 136 48 43 66 89 71 60
Col1 through Col9 are the column heads for:
ITEM DESCRIPTION CATEGORY TAX COST PRICE LOCATION QTY MEASURE
If you set a column's width to "0" by double-clicking any of Col1 to Col9 and entering "0" , the column goes away and does not reappear on next run.
I did not see a way of posting screenshots so Here they are.