Samsung GT-S5830I can't connect with kies, and after the connection, it shows "kies2.0 doesn't support this device". How to solve it?

According to your description, I suggest you try the following operations again:

1. Check whether the Kies software is the latest version (Help-Check for updates). If not, please click the following Samsung official website link to download the Kies software again:

/support/useful software/KIES/JSP

After the download is successful, turn off USB Debugging (Settings-Application-Development -“USB Debugging checkbox) and reconnect.

2. If you still can't connect after downloading again, please click the "Tools" option at the top of the Kies software page, then click "Solve Connection Failure" in the drop-down tool, and then try to connect again.

3. If you still can't recognize it, please click the "Start" option on your computer to check whether the Windows Media Player11driver is installed (it is recommended to download and install it manually, but it can be downloaded by Baidu search, and it cannot be used after unofficial installation).

4. If you still can't connect through the above methods, please switch to another computer to try the operation.

I hope the above will help you, and thank you for your support to Samsung!