virus changes mac

i have this weird thing in which my mac address changes everytime i boot up...i observed it becoz my software wont work because the hostid is changed so i have to re-edit it and change.this is accompanid by my very slow pc scrolling though im having ...

By Mary Jo Foley, Microsoft Watch October 20, 2004 While they are bullish about Windows XP SP2 (Service Pack 2), PC makers aren't putting all of their security eggs in the Microsoft basket. PC vendors are well on their way toward getting SP2, ...