void SaveActiveCurrencies()
{
var list = new List<string>();
foreach (var w in Eng.Wallets)
if (w.Enabled) {
list.Add(w.CurrencyName);
UserAppRegistryKey.OpenSubKey(w.CurrencySymbol, true).SetValue("Mining", w.MiningEnabled ? 1 : 0);
}
UserAppRegistryKey.SetValue("ActiveCurrencies", list.ToArray());
}