how to create wi-fi from dongle and get it at pc

my pc is in a multistory building, so there are floors above, and flats on this floor on all sides.

thus, by the time the net signals reaching my net usb dongle put in my pc in the inner rooms, these signals are so weakened that speed I get is pathetic or often it doesn't even connect to net.

1. Last week I saw a new micromax usb dongle in market that gives wi-fi signals. but as I already have dongle, I don't need that donble, I just need a device in which I can plug in my usb dongle, and it will give wi-fi to some 4-6 meter area.

What are such devices called, if available?

Then I can put a power socket near the kitchen window or bathroom ventillater, and put "that" device in that power socket and put my dongle in that device so that it gets strong signals from the open window or ventillator, and then give wi-fi signals to my other rooms, so that the signals reaching my pc are strong enough.

2. then, what device I need to put in my pc to catch those wi-fi signals sent by the above device?

so, my queries are - how to create wi-fi from net usb dongle and how to get those signals at pc.

Thanks.
--
Rawat

add:
I have already seen and tested that if I connect a long (15 feet) usb cable to my pc and put dongle to its other end, and put that dongle to near some window, the signal strength and the connectivity is hugely increased.

But, then connecting such a long usb might be decreasing strength itself, or when I disconnect the net, it takes a very long time to get disconnected. If the usb dongle is directly plugged into the pc socket, without the intermediate 15 ft cable, then it disconnects quite instantly when I give the command.

So, I want some alternative other than using such a long usb chord.

Thanks.