Hi my computer keeps crashing sometimes with the usual blue screen incomprehensible (to me message)not always the same.Other times I get a black screen with a dangerous looking red box contained within are the words "attention signal frequency is out of range 21khz please change signal timing" Any ideas what that means and how I go about doing what it says? I am guessing this is a hardware problem as I have already installed a previously working windows C disc to try and solve the problem but to no avail. Any info you require please ask 800 athlon cpu 40 gb Hd all in wonder pro, mitsubishi diamond pro monitor etc Thanks for reading this Ps I have looked at other responses to similair problem but no help

It sounds like your refresh rate is too high for your monitor. Try using optimal or default settings.

Thanks vtech,but you are talking to a thickie here how do I change the refresh rate is it something I do within in windows or straight to the monitor Thanks

this is what you do to change the refresh rate: somewhere on your desktop( it doesn't matter where as long as it is not on an icon or your taskbar at the bottom) right click and go to properties. you should see a settings tab at the top. click it! at the bottom of this screen you should see an advanced... button. click it. At this screen you should see an adapter tab. after clicking on that you should see where to change you refresh rate. if this dont help, try your help option in your start menu