Ok, I took a closer look at your code and two things come to mind.

1 You can drop the /s parameter. You are copying a file. The /s parameter is for copying folders including empty folders.

2 The @ldrive macro already has a trailing \ so you should remove the first \ after @ldrive.

Please give the code below a go and let us know the results.

$Result = CompareFileTimes (@LDRIVE + " Screensaver\nwdass.scr", "C:\WINDOWS\System32\nwdass.scr")
If $Result = 1 Or $Result = -3
	Copy @LDRIVE + "Screensaver\nwdass.scr" "C:\WINDOWS\System32\nwdass.scr" /h

- Chuck Norris once sold ebay to ebay on ebay.