I have an acerdesktop model am3910 - e3122.hat a windows 7 premiume.i House haveto install windows xp for some programs, but I can't. I have an acerdesktop model am3910 - e3122.hat a windows 7 premiume.i House haveto install windows xp for a program but I can't not._please you please help me how to install windows xp I have the two windows.