RoboticBuddy said:
You sure? Okay, thanks guys!
Yeup that's the one, however you should only need it if you're doing an re-installation. If you're not and you're using it for something else then ignore the following paragraph.
If you're doing a reinstallation, you have to have an install disc with the same Windows XP version as you bought it with. So for example, that Acer seems like it came with Windows XP Home Edition. If you're using a CD with SP2 or SP3 and the original computer came with SP1 or maybe even not an SP, then its going to reject your Product Key because the newer SP's will have a list of all the used Product Keys and yours will be listed. If you're using a CD with exact same OS with the correct SP, it will allow you through installation. However, once at your desktop it will connect to the internet and Microsoft will inform you that that Product Key has already been used. This is when you call them up and tell them you need it renewed because you're reinstalling the OS on the same system and they'll renew it for you.