I was thinking of buying an OEM version of XP, and I want to know what is the downside to buying an OEM, besides the no fancy box, and no manual. I heard that you have to call in order to activate it. Now do you have to call every time you reformat for example to reinstall windows? I also heard that you can only use it once? If that is true forget that. I reformat 1-3 times a year.