you will need a bootable linux cd or floppy to get access to the filesystem.
e.g.
http://www.lnx-bbc.org/
i can give you more information on this, but it can be quite complicated.
what was the first problem you had that you fixed? - i'm guessing filesystem errors
i once forced a run of fsck over my root partition [when it was in use] - something you never do. I ended up corrupting half the partition and having to reinstall everything. :s