First thing I reckon would be to use the LiveCD to copy those files you want kept out onto media. Before it all gets any worse.
+1
Further: When you are running LiveCD you don't see
/, /home, /root on the HD because those are assigned now by LiveCD and sit in the RAM. They are different

If you didn't succeed to overwrite your HD PCLOS partitions

with the Windows installing attempt then I suppose you've lost your MBR
only.
Try to fix that from LiveCD session running Menu-->More Applications-->Configuration-->Redo MBR (Restore MBR)
Add: Please also run in Terminal command
fdisk -l as root in order to see your HD partitions and post the output here.