Windows/Screen Saver

HKEY_CURRENT_USER\Control Panel\Desktop
 ScreenSaveActive 0

Then restart your computer or log out and back in to apply the changes.

--

HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\Control Panel\Desktop
 ScreenSaveActive (REG_SZ) - 0
 ScreenSaveTimeOut (1800) - 9999

ref:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\Control Panel\Desktop]
"ScreenSaveActive"="0"
"ScreenSaverIsSecure"="0"
"ScreenSaveTimeOut"="9999"