Root has nothing to do with your pc not recognizing your phone. Let's try fixing it first. Here's what I want you to try...
1. Right click on my computer.
2. Choose Properties
3. Choose advanced advanced system settings
4. from the hardware tab click "device installation settings"
5. select "no,... Never install driver software from windows update.
Close
Now do the following
1. go to your computers control panel / add and remove software (win xp) or programs and features windows 7.
2. Uninstall Kies and Samsung drivers.
3. When complete, restart computer and phone.
Download these Drivers
4. Install the drivers on your computer but do not plug in your phone until it has completed.
5. plug in your phone that is already started. It should now recognize your phone and at the bottom right corner say it is installing the software for your phone. click on view details. Several drivers should load and as it progresses green checks will appear when successful.