I use Directory Opus 9.1.1.5. Every I bring out the Find tool window, the search string in my previous search remains there, and I have to clear them again and again. Is there a way to automatically clear them? Thanks!
Did you read this post: [url]Clear search mru?] 
I get it, make a empty (or preset) find.osd and make it read-only. Thank you!
DOpus saves the last searched Name and Text in the file
..\Documents and Settings<your name>\Local Settings\Application Data\GPSoftware\Directory Opus\State Data\find.osd
If you open the XML file in Notepad, you will find the last searched Name and Text here:
<name>Name</name>
<contains>Text</contains>
Change this to:
<name />
<contains />
Note that when you just delete find.osd, all your settings (clear previous results / show results in / search inside subfolders etc..) are also deleted!
But yes, you could change the settings and make find.osd read-only! 
Some extra info: Deleyd created a great button / script (with a detailed guide) to clear the Find Dialog fields.
You can download it here: [url]Clear the find fields before searching for more files]