Not long
It can grow mold if it is left unrefrigerated for a long time. But it is unlikely to spoil otherwise.
can i boil potatoes in my halogen cooker
No it does not, maybe in a matter of days it will though.
a couple of weeks almost a month
Yes it can spoil with out refrigerated.
No need to boil, just grate & then fry.
Four hours at room temperature after that it begins to spoil.
I wouldn't eat them after 30 minutes out without cooking them thoroughly again.
you can cook potatoes by boiling it or you can bake the potatoes. if your baking the potatoes, you boil it for like about five or ten minutes and then bake it
if you put potatoes near salt it while dry them out.
That would depend completely on how long they have been unrefrigerated and if there has been any bacterial growth or contamination. If you don't know, it would be safest to discard the food.