Due to limitations of the MBR partitioning scheme you can have only 4 primary partitions. You obviously tried to create a 5th primary partition, so Windows automatically converted all your partitions from
dynamicto satisfy your intention.
Ubuntu will see only one big partition and is not able to see how this big partition is split into several
dynamic partitions, as this is a totally Windows-internal thing. It is not possible to install Ubuntu in such a
You will have to convert the
dynamic partitions back to
basic partitions and surely you will have to delete the newly created partition first, otherwise the conversion would probably fail. All this you have to do from within Windows. The guides I found in the Internet will mostly recommend to install a third-party partition-manager in Windows which has the capability to perform the conversion, I will not recommend any software here, just search for
convert dynamic disk to basic and you will find something, probably you have a good partition-manager installed already.
If everything is done successfully you will have to change your partition layout. If you have four primary partitions already but you need more partitions you have to convert one of the primary partitions into a
logical partition (do that from within Windows with your partition-manager). This will create an
extended partition which contains the converted partition. In this extended partition you can create more logical partitions, off course, you will have to resize the extended partition or the logical partition in it first to make space for more logical partitions. This creates unallocated space within the extended partition, leave the newly created free space unallocated.
Now you can install Ubuntu in unallocated space using the option
Install alongside Windows or, if you want more control, the
The whole thing might be a bit confusing, especially if you are not familiar with partitioning. Converting and editing partitions goes always with the risk of data-loss, so the most important thing is to create backups first, at least back up your personal data.
The simple way around all this confusing stuff:
Purchase a second HDD/SSD (they are really not such expensive), attach it to your machine, only convert the Windows-drive to
basic disk and install Ubuntu on the new drive (if you don't convert the Windows-drive to
basic disk you would have to choose the OS to start from your BIOS boot menu, this wouldn't be convenient).