I have a 2 TB external hard drive. It is working fine in other laptop. but when i am trying to connect in my pc dell it is not detecting. i am having windows 7 os and i formatted my pc few days back and reinstalled the os again. after that this problem is happening with the hard drive. Even my pen drive is also not detecting in my pc. i tried to conncet with all ports but no results. kindly help me what to do.
This sounds a lot like a driver related issue.
How does the drive appears in Device Manager? In case there is a yellow mark on it, you can right click and update the drivers.
You can also go to your MOBO's website, find its USB drivers and update/reinstall them.