Hi
Very good advice from Alabalcho ,just to add that if you have heard of coil whine where coils in the PSU or graphics card can make a high pitched noise.
Well those same coils can also make radio frequency noise and it is this that will be interfering with your radio.
To mitigate it,as above,your pc needs to be earthed which if you are in the UK it almost certainly will be unless you have a fault on your earth connection.,and your case should be entirely metal ie with no side window.
You might find that if you turn your PC 90 or 180 degrees it will reduce the interference or move or rotate the radio.