Try this:
Immediately after the line
var builder = new OleDbCommandBuilder(dbAdapter);
add the two lines
builder.QuotePrefix = "[";
builder.QuoteSuffix = "]";
That will tell the OleDbCommandBuilder to wrap table and column names in square brackets, producing an INSERT command like
INSERT INTO [TableName] ...
instead of the default form
INSERT INTO TableName ...
The square brackets are required if any table or column names contain spaces or “funny” characters, or if they happen to be reserved words in Access SQL. (In your case, I suspect that your table has a column named [Password], and PASSWORD is a reserved word in Access SQL.)