The PortableGIMP.ini file has a spelling error for the GTK-bin
directory:
it should be changed from:
gtk\gin
to:
gtk\bin
But any way, you will get an error during startup that the system was not able to find gtk libraries. In the PortableGIMP.nsi the following lines need to be changed:
90 StrCpy "$GTKDIRECTORY" "$EXEDIR\$0"
92 StrCpy "$SETTINGSDIRECTORY" "$EXEDIR\$0"
The $EXEDIR should / must be removed.
Already a known issue. Search the forums. Will be fixed in the next release.
Sometimes, the impossible can become possible, if you're awesome!
ups sorry, but i did not find anything about the $EXEDIR, which need to be removed.