Hmm, i have quite a few custom built PC's and only once have i needed to activate windows. And yes, i have before used illegal copys of Windows which has no activation, but i've got all genuine copys now and i've only needed to activate once. on my lappy-top it doesn't need activating and thats a Genuine Windows XP Home. So must just be a problem your having. Sure you don't have a virus thats deactivating Windows?