Have had to revert back to Studio 4.7 cos of program bug
in The Commons
So, I asked this question some time ago and also put in a bug report: how do I stop Studio from changing the render engine from 3dl to Iray within three seconds of my opening the program. This is with an opening scene that is set to 3dl. I've tried everything that was suggested, the bug report was unsuccessful, I reverted back to 4.9, no joy, I uninstalled everything to do with Daz and did a full registry clean, no joy. I tried 4.8, still no joy. So, I have abandoned 4.8, 4.9 and 4.10 and gone back to 4.7 where there is no Iray. Does anyone have anymore ideas? I don't have this problem on my laptop, running exactly same Windows 7 64bit. I hate computers.
Cheers
Lorraine

Comments
my experience with 4.9, it remembered which engine i'd used last.
did you clean out your local app data for daz? cant remember if was under roaming app or local
I'm running 4.9.2.70 and the latest 4.10 public beta on a Mac using 3DL and never had that occur, both versions always remember the render settings. I have no idea what could cause that
. If it still reverts to IRay in 4.7 you know there's something seriously wrong with your computer
...can't 4.7. only has 3DL. Iray didn't appear until the 4.8 Beta.
Lol it was a bad joke
..wasn't sure judging by your post total. I've seen people here rack up that many posts in less than a year.
Have you tried "Defaults" button in the Render Settings panel? Sometimes this fixes weird issues like that.
Thanks for the advice, peeps. Have tried all these things, the only thing I haven't done yet is do a clean install of Windows and reinstall everything. Happy puttering along with 4.7 at the mo so I'll leave that for another time when I have more patience and fortitude.
On a level of drasticness, this is kind of like giving your car a complete workshop tear-down and rebuild because the ashtray's full. There's no need to go this far, and in many cases just reinstalling DAZ|Studio like you did earlier doesn't fix the problem — the program settings are not stored with the program, so they are preserved on re-installing (this is so you don't need to totally rebuild your settings every time you update D|S).
Have you tried going into the preferences? Edit>Preferences>Scene has tickboxes for Render Settings at the bottom of the dialog; you can select whether or not to use the Render Settings in a scene you load (overriding your existing settings), and whether or not to save the Render Settings when you save a scene.
You could try deleteing the studio info in the regiistry.
I'm loath to suggest it, or offer a screen shot of the info; damaging the registry often requires a new installation of OS.
You could also do a search for Studio (Ctrl F), and consider deleting what you find; be careful.
After uninstalling Studio, use something like CC Cleaner, and let it find all the rubbish that needs deleting; personally I'd try CC Cleaner first.
As mentioned by others, delete the folders of settings too, something like: C:\Users\YOUR_NAME_HERE\AppData\Roaming\DAZ 3D
You can tell DS to record and ignor certain settings when saving and loading a scene. Hit F3 and check out the different tabs as thats where they are found. I am sure that is where you will find what you need. I personally have not experianced the issue you are currently having.