The solution in Case 00306435 was a remote session. While the SDL technician was working remotely on my computer, he asked about my mice, which in my case are three devices, and then took off one mouse option. Since then, the mouse on the laptop doesn't work, and since I noticed this a few days later, I haven't been able to find the place where the tick was removed.
Since then I haven't had much time except to make a few vain attempts to look for the unticked box, but then this morning I realised (and confirmed by disconnecting the laptop) that since the mouse on it is the one that was shut off, I won't be able to use any mouse at all while taking the naked laptop on trips. Also, I use that mouse sometimes when standing up.
I hope the same technician or someone else at SDL can quickly remedy the problem.
Sincerely,
Philip