English is not my native language. Please sympathize for my poor writing.
For example, I have a folder which has 4 files: 1.txt ; 1.2.txt ; 1.3.txt ; 1.4.txt
In Windows Explorer (Windows Xp), when I sort these filenames by alphabet (ascending), it always shows: 1.2.txt ; 1.3.txt ; 1.4.txt; 1.txt
In Directory Opus 9.5, with the same way of sorting, it always shows: 1.txt ; 1.2.txt ; 1.3.txt ; 1.4.txt
Why do Windows Explorer and Directory Opus have this small difference and How do I force Directory Opus to show the filenames like Windows Explorer ?
Thanks a million for your responses
You can try out changing
-> tools -> folder options -> display -> sorting options > numerical file name sorting, then save for all folders (pleaase make a back up first, in -> options -> backup).
this should change the numerical sorting.
Hmm, sorry, i just tested it & it wont´t change it the way explorer handles it. Maybe because explorer´s sorting is a bit unlogical, since
1<1.1<2 etc.
See this thread for some more discussion on Opus vs. Explorer sort options.
Regards, AB
I can't see any logic behind Explorer's sort order:
1.2.txt
1.3.txt
1.4.txt
1.txt
I can confirm that Explorer does it but it doesn't make sense on any level I can think of. The names are not alphabetically sorted ("1.txt" is a smaller string than any of the others -- Edit: No it isn't, I was being stupid! 
). They're not sorted numerically. I'm not sure how they are sorted.
I'd be asking for Explorer to change, not Opus. Perhaps there is a logic behind what Explorer is doing and this is just a degenerate case where that logic doesn't produce sensible results, but I can't think of what the logic might be.
Explorer does the same with words and letters, sorting in this order:
test.banana.txt
test.carrot.txt
test.txt
That doesn't make sense to me either. I'd expect test.txt to come first, like it does in Opus.
Ah, wait. I see what Explorer is doing. It's comparing the whole filename, including the extension. Obvious, but didn't occur to me a moment ago.
The letter 't' comes after '2' so 1.txt compares after 1.2.txt if you compare the strings including the extensions.
On the other hand, Opus doesn't consider the file extensions unless what comes before them is the same. (At least, I assume that's what it's doing.)
What Opus does seems good to me, though. It seems more natural to sort using the base names, excluding the extensions (unless the extensions are all that is different).
AFAIK there isn't an option to turn it off but if you want to see one send a feature request to GPSoftware.