turned on my xp home machine 2 days ago and it got through the cmos checks screen then flashes for an instant "invalid boot.ini file" then starts over and keeps doing the same thing over and over.

I can boot with an xp floppy, but then can't access the cd drives or the main partition of my c drive. I can dir the second partition of the c drive (which HP calls D drive when you're in windows) which has all of the windows files and recovery stuff.
If I boot with a win98 floppy, I can get to the cdroms, and the 2nd partition, but not the first. If I fdisk, I can see both partitions, and my 2nd hard drive (L: in windows), but it says that the first partition is 100% full and I know it shouldn't be (should have about 20 gigs free). I don't have an xp cd, I guess HP figures that second partition with all the files is sufficient.
any ideas on how to get this thing up and running again??
HP pavillion 522n
1.8ghz celeron
256mb ram
40 gig? hd
160gig hd
cd-rw
dvd-rw
onboard video
motorola wireless network pci card
pinnacle av/dv firewire card