You can't upgrade Windows 98 to XP - XP is based on NT and not the 9x Range and they won't upgrade.
You'll have to buy a full XP - backup all of you data - boot up from the Windows XP CD and Format your Hard Drive to install on. It will do it itself and write it in NTFS; then it will Install and you can put you data back on.
A Knight is sworn to Honour. His heart knows only Virtue. His blade defends the helpless. His might upholds the Weak. His word speaks only truth. His wrath undoes the Wicked.