I regret....I did not give my PC spec. I am using P4 3GHz with 768 MB DDR 400MHz RAM and (20+80)GB HDD. So, I dont really see any performance degradation. But take my words....Norton2006 is faster than its predecessors. Try yourself. I have used almost all of them and just dumped 2005. Though, there may be others better than this which i have not used.