I have many computers! One of them is a hobby computer that has Windows XP home edition installed. The license key is on the box. The operating system is corrupt because Internet Explorer is giving many error messages. I want to purchase a disk that will allow me to reinstall Windows XP Home Edition. Remember...this is a hobby computer...no answers telling me I am out in left field please! Anyway, I visited eBay and there are many individuals selling different Windows XP packages. What are the caveats to assist me in making a purchase...a purchase that will work!