Hi Adam,

Glad the solution passed the first hurdle <g.

Just to explain the difference. The API wizard, accurately, defines the
function as:

Private Declare Function ChangeDisplaySettings Lib "user32" _
Alias "ChangeDisplaySettingsA" _
(lpDevMode As Any, _
ByVal dwFlags As Long) As Long

The first parameter is passed by reference (i.e. a pointer in C parlance).
API calls are treated by the O/S using C language. In C Null is the *value*
0. When you pass in 0& (unqualified), which is what vbNullString evaluates
to, you are telling the O/S to reference the memory at address 0 (sadly this
is the start of the O/S memory and unless your computer is in a sad state
its value will not be zero!). By changing the call to ByVal 0& you
overwrite the function declaration and tell the O/S to use the value 0 which
is correctly interpreted as Null.

Best wishes,

Peter Beach

"adam99 " wrote in message
...
Thanks for replying Peter, it works well on my PC(further testing on
other OS will be required). I really don't like changing the screen
resolutioin but at the moment I can't get around it. I will have to put
some error handling for situations where reboots are required & those
similair to your LCD monitor.

Thanks Again,
Adam.:)


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