I have downloaded the ISO file of Ubuntu 13.04, and mounted it to a virtual disk using daemon's tool. I want to install it inside Windows, and thus launching wubi.exe with --force-wubi flag. But the installation fails every time. How can I fix this?
Wubi as far as I know has been kicked out of 13.04. If you really want to install Ubuntu, I'd suggest you booting a live usb and install it along your current Windows 8 set up.
On the install screen, just select 'install alongside Windows' and use the slider to choose the size of your ubuntu partition (reckon 20gb will do).
It's an automated process so you don't have to worry about anything as everything will be handled by the installer.
Hope this helps.
If you still can not install ubuntu, first turn off your windows defender and then try installing. You can easily install without any window messages.
As answered by Mysterio wubi has been kicked out from 13.04 and further releases...but still if you want it to install it inside windows 7/8 then follow these steps.
Make a bootable pendrive/dvd of 13.04 Note: If you don't know how to make a bootable pendrive/dvd then just google it you'll find it out.
Now plug it and note the drive letter of the pendrive
press Win+ R and type "cmd" without quotes and enter the following command
Note:My drive letter of pendrive is 'D' so you should replace it with yours.
Then, wubi will pop up and you can choose "Install inside Windows" and thereafter decide your drive in which you want to install Ubuntu, how much space you want to give to Ubuntu, your profile name and password. And click Install. Reboot and follow the onscreen instructions.
Hope this helps.
WUBI doesn support with UEFI , prepare a live CD and install alongside windows 8. Also try to turn off secure boot from your bios incase it is enabled.