sppsvc.exe is eating lot of process

Hello can anyone tell me what is sppsvc.exe? as it eats a lot of memory mostly it eats 5-6 M.B's & it starts after 30 mins after turning my computer if i disable it by going to Services.msc my desktop goes black & says Windows is not Genuine:confused: If i enable it once again then it eats a lot of memory & process around 5-6 MB's every time!!:cry: Is there any way to prevent sppsvc.exe from...