Код

SET NOCOUNT ON

DECLARE @cmd varchar(8000)
DECLARE @file varchar(128)
DECLARE @result int

SET @cmd = 'DIR /B /L /ON %windir%'
SET @file = 'rar.exe'

IF OBJECT_ID('tempdb..#WinFiles') IS NOT NULL DROP TABLE #WinFiles
	CREATE TABLE #WinFiles (Name varchar(128))

INSERT INTO #WinFiles (name)
	EXEC @result = master.dbo.xp_cmdshell @cmd

IF EXISTS (SELECT * FROM #WinFiles (NOLOCK) WHERE name = @file) AND (@result = 0) SELECT 1 ELSE SELECT 0

IF OBJECT_ID('tempdb..#WinFiles') IS NOT NULL DROP TABLE #WinFiles