In my experience, having three or more user accounts on XP does affect it's usually smooth running unless it's a real beefy model. My son used to have that problem -- freezing and general slowness with four user accounts he set up for himself, each of his two kids, and his wife. I advised him to just have one user account for every one, since when it's made a vast difference. In your case you will probably want one account for yourself and one account for everyone else to use. Two accounts should put less strain on the system than the four you have now. The idea of having separate accounts for everyone, each with their own desktop and settings, is all well and good, but in practice it does affect performance and stability on the average PC.