When installing a new graphics card is it advisable to disable any CPU OC settings untill the drivers are installed ok or can i just continue with the CPU overclocked? Also, does the addition of a new GPU affect CPU OC/memory stability in any way - i.e. do I need to do a full round of stress testing of my system once the new card is up and running?
 
Thanks

Either way is fine. However, like General Iroh wrote, just completely remove the old drivers BEFORE installing the new card.