Thanks for the reply.
'One of the panes will also tell you which repair is running': my point about that was as follows. It does not show any progress *within a repair*.
'Can you try the repair program again in Safe Mode with Networking to see if there is any change?': thanks, but I managed by other means to fix things. The most serious, underlying problem with the repair program is, I believe, the following. Due to borkedness of my system - which is exactly what the program is meant to handle - some registry keys were readable only as administrator and this meant that some of the repairs, and/or the 'pre-repair operations' - hung. But also, and as I have been saying: progress within repairs needs always to be shown somewhere; the CPU usage indicator does not suffice for that because the usage could owe to other processes.
It seems to me that these are all problems that need fixing. And if the program does not get improved via feedback such as this, then how does it get improved?