Do everything you possibly can to NOT run the desktop wireless, it really should only ever be a last resort to have a desktop computer on wireless. the only benefit of wireless is keeping a computer portable, it's is inferior in every other way and as you'll never want to walk round the house using a desktop computer wireless is never needed.
The Netgear N150 seems to be a wireless router, not a wireless dongle. and although it is undoubtedly a better router than the one you have, you don't need another one :)
this is the sort if thing you need..
http://www.argos.co.u...xt%3EUSB+WIRELESS.htm
Or if you are not too far away from the router and only use it for internet use and not copying large files between computers often a wireless G adaptor would be fine
http://www.argos.co.u...xt%3EUSB+WIRELESS.htm
(I can't find specs on your router, but while I can believe it might not support wireless b, it will support g)