Please tell us what app you installed just before the iPad quit syncing. Or, what was the last thing you did on your iPad before you noticed this problem. Or, what was the last thing you did on your computer before this. In addition, before this sync that did not work - when was the last time you connected your iPad to the computer. What version of iTunes are you running and what version of iOS do you have on the iPad1?
Knowing the answers to these questions may give us a starting point to try to figure out what's going on with your iPad.
Marilyn
P.S. Please start only one thread for an issue or question. More than one fragments the conversation, makes it hard to follow the discussions and breaks the rules of the forum. Please keep all updates, follow ups and discussions to this thread. I have deleted your other one. Thanks for your understanding.