This is the solution I got from
http://www.thegalaxytabforum.com/ind...elp-with-kies/
The Tab needs to be in "Kies mode" when connected for Kies to be able to work. To make this possible do this:
Unplug your GTab and go to Settings > Wireless & Network > USB settings
Select "Ask on Connection" -- this is the most flexible option.
When you connnec the GTab select Kies Mode and then click on "Mount" if the Mount button is displayed.
Start Kies if it doesn't start automatically, then it should work.
WARNING: Kies' initialization phase is currently buggy, at least on my 64-bit Windows 7 machines. You may need to click away 20-30 error messages and confirm that the application is allowed to make changes on your computer 10-15 times before it starts. Once the error and confirmation messages have stopped it seems to work OK, however.