my window wallet is take for ever to sync three days and it still has 10 days left
yes, it is because it is not responding
TIPS with windows wallet, close it and reopen it every 15 min or so, if you are way behind on sync'n ... thats what works for me
also, try not to multi task when it is open ... go get a coffee or something while its running, it will freeze less
see if that helps

bottom line, the wallet sucks the big one