Is there a way to tell the Windows 8 installer not to erase the grub bootloader? For example, changing something in the OEM folder or some kind of slipstream technique similar to how it is possible to automatically activate Windows?
In my case I have Windows 7 on one partition, and due to the similarities between Windows 7 and Windows 8 I would expect that there would be no need to erase the bootloader.
No, the windows 7 bootloader is not able to boot a windows 8 parition. The windows 8 boot loader is a new version ( UEFI ) that allows a secure boot option, different from windows 7, and is required to be able to boot Windows 8. Once you have windos 8 installed, you can modify the boot menu to describe both win8/win7 partitions.
No, Windows 7 won't replace the bootloader but it will set itself as the default option in the bootloader which will force the Windows 7 bootloader.
To revert to the Windows 8 bootloader, you will just need to set Windows 8 as the default option from msconfig.
I guess nobody gets me.
I can't find a way for the Windows installer to not erase the bootloader. So I think its fair to say that this is impossible.