Partitions do not appear while installing ubuntu 10.04
 

My computer is currently running on Windows 7 and I had a spare partition formatted as ntfs.

At first I tried to install ubuntu to that partition. Everything was fine, ubuntu recognized my previously installed OS and all partitions. At some point during the installation, however, it is recommended to have another partition formatted as swap.

Then I split the partition into two parts and formatted one as swap and one as ext3 using Acronis Disk Director.

Then I restarted my computer to install ubuntu to new partition. This time it did not recognize any of the partitions and said that "there are no operating system on this computer." The whole disk was appearing as one partition.

At that time, I quitted installation and go back to Windows 7, it was working properly. I booted using Acronis Disk Director and partitions were in their proper place.

I tried formatting back to ntfs and then to swap and ext3 again, nothing changed. (I also tried several other combinations, nothing worked.)

What might be the problem? I don't want to format the whole disk.

This happens to a lot of people after having run raid on their computers. To see if this is the case boot to the live cd and type in the following into the terminal:

sudo dmraid -r -E /dev/sda

note: sda is the name of your disk, which may be different on your computer.

Some text will then pop up in the terminal, and if it asks you if you want to remove raid, then select yes and remove the raid. Your partitions should now be visible.

Another solution, that I have heard works, is to Boot up to the Ubuntu 9.04 live CD and install that version of Ubuntu, then Upgrade to 9.10 and then to 10.04.

Thank you very much for the reply.

I tried the command you suggested, but I got a response saying that "No raid disks and with names "/dev/sda"". I believe that the name of my disk is sda (During installation, I saw that the name of the only visible partition -which is the entire disk- is sda).

Installation of 9.04 is no different. Partitions don't show up in 9.04, too.

Do you know a different approach that must be taken at this point?

Thanks in advance.