I was installing kies on my PC to the tablet GT-P1000 until something appeared on the screen of the tablet that I thought is not supposed to appear. Therefore, I stopped the process although it said not to. Now my tablet does not work anymore and it only shows me a phone and a PC with a problem with the connection between them. I can turn it off but when I turn it back on it would still show me the same thing. What do I do? I really need help, please

First off, is your Samsung Galaxy Tab rooted? And if so, which recovery did you flash?

If it is not rooted, you can get into the recovery mode by pressing the home and volume up keys, hold them down together, then power it on.

As far as what to do from here... if I recall correctly, there should be an option to restore to factory defaults. Give that a shot. But also take note of what options are available and post back so that if that option doesn't work, I am reminded of what options there are and what would be the next step.

NOTE: You are probably going to lose any saved information on the tablet during this process.