How to show and change "OEM (Reserved)" partition type to real primary parttions?

The problem started when I wanted to install (an additional) Windows 7 into a primary partition which was originally setup by the notebook manufacturer.

Much to my surprise Windows 7 installation told me something like
"Win 7 cannot be installed into your selected partition with partition type "OEM (Reserved)" which is protected for manufacturer".

Hmm, I restarted with Paragon Partition Manager BootCD and could not see
any partition with the partition type "OEM (Reserved)".

All primary partitions were declared as "primary".

Why does PPM not show the real partition type?

Ok, I know the partition because I know the size of it.
So I could change/convert it somehow to prepare it for the later Windows 7 installation.
But how can can I convert a "OEM (Reserved)" partition into a real primary partition with PPM ?

Matt

 

You can delete OEM partition and then create new simple NTFS partition instead.