I am trying to write a program that monitors when the screen has been redrawn. Meaning if any part of any window is redrawn, then the program is notified. As far as I understand I should use a journal record hook like at http://www.vbaccelerator.com/home/vb/code/libraries/Hooks/Journal_Record_Hooks/article.asp However, I do not understand which MSG type would get me the WM_PAINT events (WH_CALLWNDPROC and WH_CALLWNDPROCRET do not seem to do the job). I'm not even sure that WM_PAINT is what I'm looking for... Basically, if I knew when the DC associated with GetDesktopWindow() has changed then my problem would be solved. Question is: How do you monitor screen updates?