Wirh my Compaq Evo 1015V laptop screen on its way out, I bought an Acer V173 monitor to use with it. But the native 60Hz refresh rate does contribute to headaches for me and I would like to increase it by unticking the "Hide Modes that this monitor cannot display box." What worries me is the underwritten note that suggests that thses increased rates may lead to an unusable display or damaged hardware. I assume they mean damage to the display and not the computer itself. But is this an unnecessary worry if I set the rate to what is native to the external display itself? Advice please. Something like 75 Hz would probably do no end of good for my headaches.

Have a good Google of your monitor's make and model and see if you can find either information about supported refresh rates or a driver for it.

Thanks I did. It says it has a max V-Sync of 75Hz and max H-Sync of 80kHz.

You should be fine going up to a maximum of 75hz then. But try 72 first.

Before I read your reply, I tried 75Hz. I've noticed nothing wrong. Would I notice something if it was too high? If it is the maxiumum would I be better on 72Mz?

The safest option is to use the lowest that looks good. If you use too high a refresh rate you wont actually see any problems, it will just shorten the lifespan of your monitor.