You can do it using P/Invoke. This CodeProject articles describes the required steps:
Dynamic Screen Resolution[
^].
Don't do it! The screen resolution should be changed only by the user. If your application does it, it may sabotage other applications. There can be some rare exclusions from this rule. For example, you might need to produce a system utility needed to setup many computers. In all cases, this is a good idea to explain your ultimate goals when asking a question.
Please see also these answers:
change screen resolution using vb.net[
^].
—SA