hey rodis, welcome to techspot...
your acer aspire 5670 suppose to have "built-in recovery" and you need to burn the data inside to a blank DVD or few CDs.
I don't know whether you can use the built-in recovery without burning cause i haven't try it. Try not to install generic windows xp, check the manual or go to acer eRecovery settings.
The biggest fear is that if you try to install windows not from acer, you will lose your genuine windows xp from acer and also all the drivers also programs.
hope it works