As titled, I tried to install today the 15.04 x64 but it hangs at the partitioning step. 

I have a partition for window and one for ubuntu, I already formatted the ubuntu one so now I am stuck because there is no grub that can boot even windows.

It hangs after I select the ubuntu partition, select the ext4, format flag, point `/`, then I confirm my changes and then it hangs

I tried to wait something like one hour, nothing..

I tried also to not select the update and the third part software in the previous step (I read it helped in some cases) but no success.

I also noticed I can access the linux partition at the begin, before starting on "installing ubuntu" from the live desktop. Then when it hangs and I quit, I cant access it any more, it complains about some D-BUS..

I already tried AHCI and IDE mode, no success

I also tried to boot with all the "Other Options" on (noacpi, etc..) except "Only free softare", no success

What can I do?

Ps: I noticed the ubuntu partition get mounted and unmounted continuously..