To answer this question, we need to compare the games available on Windows XP and Windows 98.
Option A) Hearts - This option is incorrect because both Windows XP and Windows 98 have the game Hearts.
Option B) Minesweeper - This option is incorrect because both Windows XP and Windows 98 have the game Minesweeper.
Option C) Pinball - This option is correct because Pinball is a game that was included in Windows XP but was not available in Windows 98.
Option D) Freecell - This option is incorrect because both Windows XP and Windows 98 have the game Freecell.
The correct answer is C) Pinball. This option is correct because Pinball was a game that was included in Windows XP but was not available in Windows 98.