I had a working windows .20 version for 64 bit then installed .23 64 bit, wallet would not start correctly. Tried all the normal stuff, reinstall, uninstall, delete apps roaming folder....all to no avail. Tried to reinstall .20 version but now nothing works. App either fails to open at all or the starting window opens then goes nowhere....if you click on it, it simply disappears. Any ideas on how to proceed would be very much appreciated.