At first it will be useful to know which notebook model do you have, which operating system do you use and do you still use original Toshiba operating system.
Due to different recovery image installation methods partitions structure on old A300 or new A660 is completely different so it is not easy to say what is right or what is wrong.

Partitions structure listed in disk management is a little bit strange for me and on my notebooks with original Toshiba OS it looks completely different.
Generally speaking you should do the follow: start preinstalled operating system (factory settings) and create recovery DVDs using preinstalled “Toshiba recovery disc creator” too. After doing this you can do with your notebook whatever you want.

Please note. When you change original partitions structure, install own OS or change anything you will not be able to start HDD recovery installation and install Windows using recovery partitions. So please create recovery DVD before you start to change anything.

Back to your questions:
To be honest I don’t know why this is shown as empty. Toshiba recovery image is one big file and, as far as I know, it is not split and placed in two different partitions.
Recovery image don’t contains two parts.
I understand your question but recovery image is not designed as two separate parts. It is one “item” and cannot be changed or manipulated.
Good question. Unfortunately I don’t have proper answer to this question.
For better understanding post notebook model and which OS do you use. Is this original state you got with your notebook (factory settings)?

I already wrote. Create recovery DVD and you can change whatever you want. Later you can use this recovery DVD to get “factory settings” again. You can use these DVD discs so often you want and without any limitation.

It is a Satellite A500. It is still in the same configuration that I received it in. Although it was refurbished, when I received it everything seemed to be the same as if I had bought it from a retailer. All of the Toshiba/default programs were there (eco utility, intel turbo boost, and the usual bloatware & trials such as norton etc). The operating system is Windows 7 Home Premium.

In a couple of hours I can get you a screenshot of Disk Management if you wish.

Hi

I’m really surprised that you got older A500 with 600 GB HDD. Which A500 do you have exactly (A500-xxx)?

One more thing: on the right side there is listed partition D in this small tool (DISK). Is partition D available or not?