Is there a way to permantly replace the default .ico with a custome one?

[RhoSigma]

Easiest way,

1.) rename your qb64pe.exe to org-qb64.exe
2.) run org-qb64.exe
3.) load source\qb64pe.bas
4.) change the $EXEICON line (line 13) to your icon (with path if required)
5.) press F11 to rebuild qb64pe.exe with the new icon
6.) quit the IDE and delete the org-qb64.exe

To get all your programs using your icon just place the same $EXEICON line in your programs. That's in fact the only logic way, as all the icon.ico stuff as mentioned above is just what you placed in the $EXEICON line and then temporarily used during the current build.

Without $EXEICON or manually loading an image and pass it to _ICON your programs will always use the hardcoded image in libqb.cpp, which is in fact the same as the current PE icon.