Martin;
First, thanks for your swift reply.
Now Aceit and tgatool2c are installed. I can open an ace file and send it to my editor (Paintshop Pro 7). After saving my changed file, when I go to tgatool to reload data, the screen is blank (white with header) and tgatool is "program not responding". Can you help?
Thanks again, Lloyd

In default mode Tgastool suspends itself until the spawned program is closed and then it automatically reloads the data and activates again. This is to automate as much as possible the editing process but it does mean you have to close the paint program once you have finished editing

I you want to keep your paint program open then tick the "use old send to editor" in the prefs menu. This will switch it to the old way where Tgatool stays active and you have to manually tell it to reload the data