Can't share internet over lan

You must share your internet to other computer using your lan connection in able other PC can open internet wondows.To do this
go to my network click set up home and small office network then follow up wisard set up before you close set up insert your cd windows installer e.g. xp or vista click additional task,click home and small office network again from cd follow wizard then click finish,then insert your cd wondows installer to other computer and repeat procedure on set up home and small network restart your PC everytime you install internet sharing,be sure one PC will assigned as server