I previously had QB64 installed on a win7 machine, and it worked fine, except that the character a with two dots above instead came out on the screen  as a greek sigma. This coud however easily be remedied by holding altgr (if I remember correctly), and entering the ascii-code of the wanted character. Having now anew downloaded QB64 to use on a windows 10 machine, I find that the altgr-fix for typing special characters isn't working anymore? Or do I not remember correctly how special characters can be typed in, is it not altgr that is to be pressed down while entering the ascii code?

I also find that if you try to save a file in a path that contains an a with two dots above, (using the save as... dialogue box), an error results and the path cannot be found, because the a with two dots is replaced by sigma, just like in the editor window.
How can I solve these problems?

On my keyboard, caret (^) is normally written by pressing shift+(^¨~), and then a space. But this doesn't work, and caret is only appearing if you keep shift+(^¨~) pressed down, and dozens of them come out at once.