Anyway, those stdout.txt and stderr.txt files are created next to Powder.exe (or the Working Directory if you fiddled with the shortcut menu), but they vanish right after you close TPT. They may have at one point contained error (or status) logs, but now are exactly useless. You can write to these files within Lua scripts, though.
@Na2kiRandom(View Post) Why is "Powder.exe" on your desktop anyway? Any stamps and local saves will be stuffed into the desktop too, among with all the files you just mentioned. Try putting it in a folder and putting that folder in My Documents or some place, then making a shortcut on the desktop to TPT.
@Na2kiRandom(View Post) I would suggest you create a Games folder somewhere, store TPT in there, and then create a shortcut to the powder.exe on your desktop, as @boxmein(View Post) said. This way you can have only the important - frequently needed - software on your desktop, and all the additional files somewhere out of your way.