Thanks for the reply. My question was right. I got a laptop with XP home installed, but I messed up with the intalled OS and recovery does not work and no OS CD with the machine. I have a WinXP Pro. which I have a licence for it. If XP Home has no advantages over XP Pro, I am not going to phone the manufacturing for tech support.
I understand that Pro has some features Home does not have. My question is that is there any advantages of Home over Pro. My assumption is extra features normally require extra power, so is it possible Home is "faster (even marginly" than Pro? Another issue is that the compitability especially for some games. Security normally means restriction, so it may be poosible Home is more compitable than Pro because restriction enforced by security.