Your main problem here is your Wubi filesystem is inaccessible due to NTFS corruption on your windows filesystem. You need a windows installation CD to run chkdsk from. There is no safe way around this. However, if that's not possible, there may be something you can try - but it may make things worse, so if at all possible, obtain a windows install CD from a friend in preference to this.
Boot from an ubuntu CD. When it's up, attach an external hard drive and open a terminal.
If your external hard drive is significantly larger than your internal hard drive, do a full backup first. This will take a long time:
sudo dd if=/dev/[your hard disk device] of=/media/[name of external hard drive]/backup.disk bs=131072
Then:
sudo mkdir /mnt/host
sudo ntfs-3g -o recover /dev/[your windows filesystem device] /mnt/host
cp /mnt/host/ubuntu/disks/root.disk /media/[name of external hard drive]/root.disk
e2fsck -v -f -C0 /media/[name of external hard drive]/root.disk
sudo mkdir /mnt/ubunturoot
sudo mount /media/[name of external hard drive]/root.disk /mnt/ubunturoot -o loop,ro
[your hard disk device] will likely be either sda or hda. [your windows filesystem device] will likely be the hard disk device with 1 at the end; if it isn't, add the contents of /proc/partitions to your question and comment on this answer.
If all goes well, you will have access to your files at /mnt/ubunturoot. If things go wonky, you may lose everything on your hard drive forever. If this happens and you made a backup, you can restore it by flipping the order of if= and of= in the backup command, but at that point you really will need to run chkdsk off an install disk.
Best Answer
Are you shure that you have corrupted partition? Maybe you have erased boot-record or damaged partition table. Try to investigate the problem at first. Describe how did you installed your Linux. From your previous question it looks like it's installed on flat file inside of windows (vfat or ntfs) partition. Try to run fdisk and look at your partition table.
Before making any changes to hard drive try to make image of your hd (you can do that at your friends).
UPDATE:
As we can see there is just one NTFS patrition so I suspect that you installed Ubuntu using WUBI (or something similar).
Your Linux is installed in a loop-mounted partition which is just a file or couple of files somewhere on your windows disk c: (c:\ubuntu\disks for example)
As I see from your previous question you can boot Windows so you could use dskprobe from Windows XP Service Pack 2 Support Tools to make sure that fs type is correct ... but it's already correct fs type 7 is NTFS.
Message "The type of the filesystem is RAW. CHKDSK is not available for RAW drives." means that windows can't determine fs type for some reason. As we see fs type is correct.
To run Chkdsk on your Windows partition you can install Windows Recovery Console, boot in recovery console and check your disk.
After checking the disk you will gain access to you c:\ubuntu\disks. I think you can mount your linux partition (which is in file) as usual loop-back device:
But you should mount windows patrition first.