Installation Upgrade 12.18

Good Morning,

This morning I used the upgrade option to upgrade my Opus program from 12.16 to 12.18
Unfortunately once again when I upgraded I lost the dopus.exe file which was no longer anywhere to be found on my hard drive.
Each time I upgrade to the latest edition of the program it stops working and takes me days of fiddling to restore OPUS
What am I doing wrong - is there a clean option to delete Opus completely and restart again?
Note: Each time I try to install the upgrade it runs through the installation procedure and then produce a dialogue box that says it cannot complete and asks me to terminate.

Please see the FAQ on Problems installing Opus. Installing from another user account is usually the easiest solution when this happens.