often this works:
if it dont asks for "Firewall go through" you have done something wrong at the Installation
another try:
win 7 not working at win 8
save your wallet
delete this Folder:
C:\Users\"YourName"\AppData\Roaming\Sync
perhaps then restart your pc
redownload the wallet here
https://mega.co.nz/#!psYDQJBT!KM8qfYQc1G-6-lCOFhiQU64R0y_SMoEXzMog5NbVJE0
open it and wait 2 seconds (here win have to ask for the Firewall go through) - Close the wallet !!!!!!!
go to
C:\Users\"YourName"\AppData\Roaming\Sync
make a txt.file and rename it to Sync.conf
write in it:
server=1
listen=1
rpcuser=user
rpcpassword=pass
rpcport=24240
port=24241 "this port have to be open on the router"
addnode=23.226.225.224
addnode=107.170.10.33
addnode=80.240.140.149
addnode=86.1.252.20
addnode=90.217.94.252
addnode=207.12.89.92
addnode=162.243.157.49
addnode=128.199.189.163
addnode=162.243.103.7
addnode=128.199.187.204
addnode=95.85.31.58
and THEN restart the wallet by open sync-qt.exe
please try