thank u very much sir for info i hve learnd already btw my block has been downloaded but only 50% is this for first time ?
You only need to download the blockchain once. It contains old payments from 2009 to now. 50% is actually about 10%, because Bitcoin has become more popular recently, and there are many recent transactions to download. After your first blockchain download finishes, only new information has to download each time you start the client.