[quote=Roadling]Hello,
Is there a setting or preference that would cause double clicking on a .sql file in windows explorer to open the file in my current instance of PSD rather than spawning a new instance?
[/quote]

My tst files where opening in the existing instance but my sql files where not. I looked in the Windows registry and changed:
HKEY_CLASSES_ROOT\.sql data to PL/SQL Developer
Now the sql files open in the existing instance! I first looked at the .tst entry to see what it looked like.

Windows 7 32-bit
PL/SQL Developer 9.0.6.1665

After all this years, this is still not working! Each time I double click on a file in Windows Explorer or in my version control system a new instance is launched, which takes at least a minute in my case. This is by far the MOST ANNOYING problem of PL/SQL Developer!

Marco, how can it be a Windows Explorer problem? The Explorer knows nothing about PL/SQL Developer, the explorer can only launch a new instance with the given file. It is up to the new instance to transfer the file to an existing instance (or not doing it, depending on a user preference). This should be really no problem for an accomplished programmer.

[quote=Buckeye]
My tst files where opening in the existing instance but my sql files where not. I looked in the Windows registry and changed:
HKEY_CLASSES_ROOT\.sql data to PL/SQL Developer
Now the sql files open in the existing instance! I first looked at the .tst entry to see what it looked like.
[/quote]
This is my .tst setting in the registry:
[HKEY_CLASSES_ROOT\.tst]
@="PL/SQL Developer 14"

And this is my .pck setting:
[HKEY_CLASSES_ROOT\.pck]
@="PL/SQL Developer 14"

The first opens in an existing instance, the second always opens a new instance. So I guess is IS something in PL/SQL developer...