process The name or PID of the process to check.

priority A flag which determines what priority to set
$PROCESS_LOW (0) = Idle/Low
$PROCESS_BELOWNORMAL (1) = Below Normal
$PROCESS_NORMAL (2) = Normal
$PROCESS_ABOVENORMAL (3) = Above Normal
$PROCESS_HIGH (4) = High
$PROCESS_REALTIME (5) = Realtime (Use with caution, may make the system unstable)

Constants are define in "AutoItConstants.au3".

Success: 1.

Failure: 0 and sets the @error flag to non-zero.

@error: 1.
2 if attempting to use an unsupported priority class.

Example()
Func  Example()
; Run Notepad
Run ("notepad.exe")
; Wait 10 seconds for the Notepad window to appear.
Local $hWnd= WinWait ("[CLASS:Notepad]","",10)
; Set the priority of the Notepad process to "Idle/Low".
ProcessSetPriority ("notepad.exe",0)
; Wait for 2 seconds.
Sleep (2000)
; Close the Notepad window using the handle returned by WinWait.
WinClose ($hWnd)
EndFunc ;==>Example