Ok, here are some additional hints, how I proceeded:

First of all, make an (local) image of the whole disk - i.e. with CloneZilla - so that you can recover the original partitions every time. This image takes about 18 GB.

After that install Windows 7 as provided.

In “Computer Management” -> “Disk Management” delete Partition “HP_RECOVERY”

Reboot the Computer

Now you need to delete the small recovery partition (101 MB). It’s not possible with “Disk Management”, so

open a “Command Prompt” window ( -> Start -> Accessories), you need to run it as administrator.
Here you can enter the command “diskpart” (see “diskpart> help” for options) to localize the partition you want to delete. Normally it’s disk “0”, so you have to “select disk 0”. Subsequently enter “list partition” for the selected disk and for HP8300 you will see Partition 3 (Recovery) to delete.

Now “Select partition 3”

Deleting by “delete partition” will not work as long as you don’t use: “[COLOR=#339966]delete partition override[/COLOR]”.
[COLOR=#ff0000]BUT BE CAREFUL and INSURE FIRST TO HAVE A BACKUP.[/COLOR]

Check with “list partition” and enter “exit”

Reboot your system and check whether it works and you deleted the proper partition.

After your HP8300 started Windows 7 normally you should be able to upload your image in a way to deploy it later and in FOG you can even select “Single Partition (NTFS Only, Resizable)” now.

Hope this helps.
Greetings from Bonn, Germany.