Thanks for the Reply. The Links are really helpful
About my findings:-
The main reason after our analysis is coming out to be the I/O latch and the avg cpu utilisation of the server is 40% and most of the time the SQL server is waiting to read from the disk drive.
Also the Db files are actively/continuously scanned by the Antivirus
So can you suggest what can be done
Also today i have the following error can you help me why this came
Date1/19/2011 12:37:15 PM
LogSQL Agent (Current - 1/19/2011 12:40:00 PM)
 SQLServer Error: 121, TCP Provider: The semaphore timeout period has expired. [SQLSTATE 08S01]
Should i go to the network team for the connectivity issue or the storage team to check the storage as it is taking time to read from the SAN Drives.
NEVER NEVER EVER GIVE UP;-)