WinXp + ubuntu unmount ubuntu because the startup Item after xp and ubuntu are installed is started by grub, If you directly format ubuntu, xp cannot be started. You can choose to repair xpMBR and then delete the linux partition. Step 1: Download The MbrFix tool from the repair MBR and copy the MBrFix to a directory in the XP system. win + R cmd enters the dos environment and switches to the directory where the MbrFix is located. Run the command mbrfix.exe/drive 0 fixmbr, And the xp startup Item is fixed. Step 2: delete the built-in partition tool for Linux partition win7, but xp does not. Therefore, you can download an pqpartition magician or Diskgenius partition tool to format the linux partition. (We recommend that Acronis Disk ctor, a powerful partitioning tool, be able to directly change the size of the C Disk.) After restarting, xp is only available. The combination of Windows 7 and ubuntu uninstalls ubuntu in a similar way.