Comment 2 for bug 115217

I did some experimentation and here are the results:

Using standard settings (10 gig + 10 gig) install crashes during
virtual disk format at 33%
Using settings (5 gig + 5 gig) install stalls during virtual disk
format at 33% then crashes at 83%
Using settings (4 gig + 4 gig) install stalls at 33% then continues
and finishes installation.

With all settings, I get multiple warnings: MBR cylinders doesn't
match BIOS, MBR sectors doesn't match BIOS.

After reboot, system begins to load ubuntu, I can see logo. Then it
exits to shell. It can't find apt-get. Checking PATH, I notice that
/usr/bin is not on it. I load /etc/bash.bashrc into vi and add
/usr/bin to the path. When I exit shell, it continues to load and
gives me user box. I enter the user name and password given during
wubi install, system can't find it.

So I reboot. System loads and exits to shell giving me error:
Filesystem check failed. Exiting shell continues to load to user
selection box. Again, system can't find the user name/passward I
entered during wubi install.

I hope this helps, there is nothing further I can do.