The active flag was not set to one of the partitions during the installation. For older mainboards this flag is also necessary.
Here is the solution:
Set this flag manually by the use of
fdisk. Then start the rescue system and log in as user
root.
With the command
fdisk -l you are able to figure out the device name of your hard drive.
Here an example: An IDE hard drive is connected at the primary IDE controller as Master:
Please type in successively:
a to activate the partition
1 to choose the first partition
w to write the changes
It is irrelevant for which partition the active flag is set.