Installation problem via wubi.

[ChanderkantU4ORIA]

Hi, i am a beginner, trying to install ubuntu via wubi. For some days i was trying ubuntu from a live cd. last night it went wrong- i was booting my pc through a live cd, and suddently power went off. Today when i tried to boot-install it did not run, and gave me error "authentication failed". I have win8 on c: drive. And d: is empty(i am trying to install ubuntu 11.10 on it).
Pls help

[sahabcse]

Reformat the D drive and reinstall the wubi on it.

[ChanderkantU4ORIA]

The disk is formatted everytime i try to install ubuntu 11.04

[ChanderkantU4ORIA]

Oh. I format the disk manually. Before installation. Still same error.