回複：係統重裝是否要重新買xp軟件？有人說可去電腦品牌的網站下載，是這樣嗎？

You just need call Microsoft to re-active your XP as long as you have a XP licence. Just tell an Microsoft representative you need re-install XP. Even if you install an OEM XP, you still need call Microsoft to re-active your XP.

Linux is a better choice in long term.