U can do one thing!
Since its showing
NTLDR is missing, so u can't boot into 98 too.
Boot ur system into DOS using 98 setup CD and give command:
sys C:
Restart the system and now u can again boot into windows 98.
Now Boot into Windows 98 and goto the DUMP folder of windows XP (where u copied the XP setup) and start the installation.
( Same can be done using XP CD)
It'll start installing and will show like 52 minutes remaining and after a few minutes it'll ask for rebooting.
Now the trick comes
Restart ur comp and VOILLA, it'll show the boot loader.
Now again boot into 98 and edit ur
Boot.ini file and replace the entry of XP to:
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windo ws XP Professional" /noexecute=optin /fastdetect
(if u hv XP installed on C:\ drive )
Also make it default!