according to your description,it could be a faulty.
I suggest you to cantact the retailer for a replacement.

There could be several reasons for your adapter to continually disconnect from your network.
One of the first things to ensure is that you're connecting your adapter directly to a USB port on your computer and not through a USB hub. I would also make sure that you're not too far away from your wireless router/access point since an extremely weak signal could cause the connection to drop.
Another possibility is that you have some kind of appliance or electronic equipment causing interference. Things like microwaves and cordless phones are known to cause interference problems. Other wireless networks can also interfere with yours if it is close enough. This can often be remedied by changing the channel on which it sends the signal. Most routers are set by default to use channel 6, so you could try changing yours to something else.
If none of the above suggestions help, you may want to try uninstalling any software and drivers related to the adapter and start fresh by installing the most up to date drivers and software again.