I'm trying to use the software in Singapore but it stated that no Internet connection when I tried to register, and I have Internet connection actually.
The developers of BEIT are The Association of Consulting Engineers Malaysia. I've checked their website (which is still available by the way) and located the BEIT download page. They've said that the downloads are closed for maintenance, but that story was published 5 years ago which leads me to the next thing: the software gives you that error because there is no server it can reach to get the data.
You will have to contact them to check the status of BEIT because this is the only way, even if you have an Internet connection: http://acem.com.my/index.php?option=com_contact&Itemid=3