How to apply display change in VB without logging off

Hi, I'm able to change the width of all scrollbars system wide by writting to registry but it seems I cannot apply any changes right away from VB.
Like when you do this from your display properties, the change takes place right away.
The only way I've been able to do it so far is by using ExitWindowsEx API to log off windows.
Problem is I'd like to be able to apply the changes w/o logging off.
Any suggestions?

This is the registry key that will let you change scrollbar width btw:
HKEY_USERS\.DEFAULT\Control Panel\Desktop\WindowMetrics\ScrollWidth: "-240"


Also anyone know if there's an API to determine if vertical scrollbar is present?

Thanks in advance,