was changing the resolution on my display and hit the wrong thing the screen went black and the message "video mode not supported " came on and can not do anything Help
If you have an LCD monitor, it has a native resolution and you should use ONLY that resolution. If you trying to change something, like the size of your desktop icons, there are other was to do that.
Old CRT monitors typically have a range of resolutions but most don't support every resolution and refresh rate. You'd have to check the owner's manual for supported resolutions.
When you change the resolution in Windows you typically have to click "accept" or the change reverts to the previous setting automatically. What's happening now, you have no display or is everything just wacky?
maybe system restore from a f8 start up boot menu
or maybe also f8 safe mode.. then change setting back if will let you.