Winxp help

My computer locked up in the middle of a defrag. I cannot access my 200 gig drive. From a win98 boot disk it shows 10 megs free. I tried to re-install XP but it says I have no room. There are over 100 Gigs free.Called Microsoft and Western Digital but they could not fix it. I get NTLDR is missing when I try to boot without a boot disk.I tried to slave the drive with no success. System is a P3 800 with 256 ram. Drive is new WD and XP is home edition. Hope someone can help.Frustrated as I really need the files on this drive.Thank you for anything anyone can do or being steered in the right direction.