You can use a USB extension cable to reach better signal areas, but, you need to remember that you will also gain loss of signal over the length of the cable. You can do a screening bodge with foil, but, it doesn't really work very well...
Does the dongle work plugged directly into the computer??? If it does then you don't need the new ports.. If your computer is over 10 years old, then you may be struggling with USB 1... USB 1.1 it should function...
As has been mentioned, there are USB 2 cards available, readily available for under 10 quid (PCI, Desktop/Tower). which are easily fitted (Switch computer off at the wall, but, leave plugged in to keep the box earthed and you earthed when you put bare skin against it). Remove top/side, remove suitable blanking plate (hold card over the white slots until you see one that will take it), push card into slot and replace screw/clip that held blanking plate in position...
Start your computer up and it should go to windows and tell you it has found it, install the drivers, switch off, put your computer back together and use as normal...