I had -0018, -0019, now using -0021 (and have been for a while).
Windows Vista
Older sketches kept opening with -0019 when double clicked.
So I deleted the -0018 & -0019 folders.
Now I can't get the file associations for .pde to be with -0021.
How do I get that set up again?
When I open Windows Explorer, select one, choose Open With, Arduino does not appear in the list, and when I browse to it, I still can't get it to select it! So I have to start Arduino every time and then browse to the folder where the .pde is.
Computer\HKEY_USERS\ - some number - \Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts.pde\OpenWithList
as -some number- might differ you should use seach.
I removed the entries here so windows "lost" all associations. When opening an .pde file windows will ask for the association, use browse to select Arduino21 and it worked as intended.
I was having the same problem with Windows 7. I also found it necessary to remove some other registry entries including "arduino.exe." Sorry, I didn't make note of where the entries were, but I found then easily with a registry search.
EASY FIX TIP: If you don't want to be bothered making registry changes, you can work around the issue by renaming the new arduino.exe to something like arduino22.exe. Then you should be able to re-associate .pde files with the new version by the standard means (Right click file. -> Open with -> Choose default program...).
you can try first setting the association to something else like notepad then set it to the new arduino.exe
That was actually one of the first things I tried before searching the boards, it didn't work. I also tried renaming/moving/deleting the original arduino.exe that the .pde files where associated with so that windows would notice that it no longer existed, and would hopefully automatically disassociate it, but *icrosoft's "latest and greatest" operating system failed to release the broken association. Perhaps this problem would have been easier to correct if *icrosoft hadn't remove the file type manager that existed in their earlier OSs.
cubemike99, as far as I know you are correct, that is the quickest and most foolproof way for Windows XP. However, if I am not mistaken, that very File Types tab vanished with the release of Vista and 7. Why did *icrosoft remove it? The world may never know! [smiley=huh.gif]