Lar
A good suggestion, but in this case, I'm sure that's not the resolution. Why? Let me try and explain.
Only on my current computer have I had J: drive as my main system drive. That came about when the drive was built because I have many hardware items that are assigned a drive allocation. The tech who built this computer didn't notice and re-allocate the drive letters -- which is what I would have done
By the time I noticed this, Win XP was installed (again by the tech) and I'd installed several applications (including Opus) to J:. Over the next couple of months I detected not problems with any software, so I decided to leave things as they were. Had there been problems I would have used Ghost and Partition Magic to reassign drives and move programs.
(actually a hidden benefit has been that some "nasties" which have tried to install in the background have failed because C: just happens to be assigned to a drive for a card reader, and I rarely use it)
Over the years I've installed Opus on different drives, but after one bad experience, I
never move Opus or Opus pubs across drives. Actually, I prefer not to move pubs to different directories