This is most probably due to a cabling defect, if you've already re-installed drivers/software. Try with another cable. If that doesn't help, restart your phone.
To ensure a correct driver installation, do the following:
- Disconnect your phone from the computer
- On your PC, open device manager.
- Remove everything that has to do with your Samsung phone. That is, right click it and select uninstall...
- Reboot PC*
- Re-install every piece of software or drivers from Samsung before reconnecting your phone.
- Reboot PC*
- Connect samsung device and let Windows configure the drivers.
* Rebooting may not be necessary but it's the safest way when dealing with drivers.