Did you do everything here:
New cable and different USB port?
Disable AVG AV and the comnputer's firewll
Runs this and see if the results help with determine the cause
Try on another computer to help determine if computer or iPod problem
thanks for your reply but the problem is with my computer i connected it with other computer and it was working fine but not in mine ...
what to do not to solve this problem?
i also tried sharepod but it says device could not be found as itunes is not installed ... i am facing this problem please help
thanks in advance..