He might want to experiment if his rig is more stable without sidebanding.....
To answer your question you can disable/enable sidebanding or fastwires with WPCREDIT. I just managed to enable sidebanding in my PC and saw a huge improvement!!!!!
This will work with a chipset that don't have a BIOS setting to anable sidebanding. It will work with 440BX and VIA. You will need to check all the entries to find were is the bit you need to change.