SQL Server 2005 IO Problem

We have a database of 60 Gb the performance of it is very low. I want to find out if there is any IO problem with the server.

I have run the below

WITH DBIO AS
(
 SELECT
   IVFS.database_id AS db,
   CASE WHEN MF.type = 1 THEN 'log' ELSE 'data' END AS file_type,
   SUM(IVFS.num_of_bytes_read +IVFS.num_of_bytes_written) AS io,
   SUM(IVFS.io_stall) AS io_stall
 FROM sys.dm_io_virtual_file_stats(NULL, NULL) AS IVFS
   JOIN sys.master_files AS MF
     ON IVFS.database_id = MF.database_id
     AND IVFS.file_id = MF.file_id
 GROUP BY IVFS.database_id, MF.type
)
SELECT db, file_type,
  CAST(1. *io/ (1024 *1024) AS DECIMAL(12, 2))AS io_mb,
  CAST(io_stall /1000. AS DECIMAL(12,2))AS io_stall_s,
  CAST(100.*io_stall / SUM(io_stall)OVER()
       AS DECIMAL(10,2))AS io_stall_pct,
  ROW_NUMBER()OVER(ORDER BY io_stall DESC) AS rn
FROM DBIO
ORDER BY io_stall DESC;

**************************

OUT PUT

WITH Waits AS
(
  SELECT
    wait_type,
    wait_time_ms  /1000. AS wait_time_s,
         100. * wait_time_ms / SUM(wait_time_ms)OVER()AS pct,
         ROW_NUMBER() OVER(ORDER BY wait_time_ms DESC) AS rn
      FROM sys.dm_os_wait_stats
      WHERE wait_type NOT IN ('CLR_SEMAPHORE','LAZYWRITER_SLEEP','RESOURCE_QUEUE','SLEEP_TASK'
,'SLEEP_SYSTEMTASK','SQLTRACE_BUFFER_FLUSH','WAITFOR', 'LOGMGR_QUEUE','CHECKPOINT_QUEUE'
,'REQUEST_FOR_DEADLOCK_SEARCH','XE_TIMER_EVENT','BROKER_TO_FLUSH','BROKER_TASK_STOP','CLR_MANUAL_EVENT'
,'CLR_AUTO_EVENT','DISPATCHER_QUEUE_SEMAPHORE', 'FT_IFTS_SCHEDULER_IDLE_WAIT'
,'XE_DISPATCHER_WAIT','SQLTRACE_INCREMENTAL_FLUSH_SLEEP', 'XE_DISPATCHER_JOIN')
)

      --filter out additional irrelevant waits

SELECT
  W1.wait_type,
  CAST(W1.wait_time_s AS DECIMAL(12,2))AS wait_time_s,
  CAST(W1.pct AS DECIMAL(12,2))AS pct,
  CAST(SUM(W2.pct)AS DECIMAL(12,2))AS running_pct
FROM Waits AS W1
  JOIN Waits AS W2
    ON W2.rn<= W1.rn
GROUP BY W1.rn, W1.wait_type, W1.wait_time_s, W1.pct
HAVING SUM(W2.pct)-W1.pct < 90-- percentage threshold
ORDER BY W1.rn;

************************

OUTPUT

Please help me to drill down to exact problem area.