Sync Using Kies
As mentioned before, using Kies is a bit of a gamble, as it is possible that Kies may not even work with your Samsung Captivate. To download and install Kies, navigate to the official Samsung Kies download page and download and install the software to your computer.
After you have downloaded and installed Kies to your computer, take the USB cord that came with your Captivate and plug one end into your phone's USB port and the other into your computer’s USB port. This should automatically cause Kies to open and begin recognition of your phone. If it does recognize your phone, then you are all set. If not, there are a few steps you can take to see if you can get Kies to work.
Obtain an unlock code for your Captivate through, either your carrier (most likely AT&T), or a third party website. Once you have the code, remove the current SIM card from your phone and insert a SIM card from a different network (such as T-Mobile). When the phone asks for the unlock code, enter in the code you obtained to unlock it. With the phone unlocked, press the “Menu" button and select “Settings." Select the “Applications" option and choose “USB." Select the “Samsung Kies" option (if it appears) and connect your phone to your computer with the USB cable. If Kies recognizes the phone, you are good to go. If not, there is still another option.
The other option is to unmount the Captivate’s internal SD card, though you should be aware that this will delete photos, videos, contacts and other information stored on the card. To begin the process, press the “Menu" button and select “SD Card and Phone Storage." Choose the “Unmount SD Card" option and wait until a message appears stating that the card is unmounted. Select the “Format SD Card" option and, when the message appears stating the phone is done formatting, select the “Mount SD Card" option. Connect the phone to the computer with the USB card and see if Kies recognizes your Captivate. If it does not, you will need to try another option rather than Kies.