100.SOLUTION :

The hard disks could be working in PIO mode while in Windows 98. DMA mode for storage drives is enabled by default in Windows XP, but not i Windows 98.  To enable DMA for your hard disk, open Control Panel > System > Device Manager. Double click the hard disk under the disk drives branch to bring up its properties. Under the setting tab, check the box next to DMA. On rebooting to Windows 98, you should  be able to notice the difference in performance.  For the same reason games also do not respond well in Windows 98.