user not recognised and password not accepted during login

[Haneef Bashir]

after having to reinstall karmic to get grub to work, and downloading
and installing all my software packages all over again and updates, i
restarted my computer to find out that i could log into my account. i
went to recovery and dropped to terminal to see it i can fix the
password. when i try to fix my password it says user does not exist.
when i use the live cd i can see my home folder on my home partition.
i do not want to delete my home folder and make a new user account
with the same name or what ever. this is the second time this has
happen since using karmic. any suggestions on how to fix this?