Hi,
Win7 on an old Thinkpad T500. Want to install Kaos as dual boot. I searched the forums and I am not quite sure, if I can do this-your suggestions? If I am not happy with Kaos-how to remove it, without killing Win7?
Thanks for your replies!

Morning,
Maybe you can first try KaOS using Virtualbox from Windows without touch your system.

As suggested above, you can try first without installing. You can do so in virtualbox, or just run it in live mode a while.

KaOS by default installs the bootloader in MBR, this will overwrite the Microsoft entry. Removing KaOS does not touch the MBR, so you can still access Windows from the bootloader. Just the KaOS entry in that bootloader will no longer work.
Other option is to install the bootloader in the root partition of the KaOS install (the installer will give you that option). But that makes booting into KaOS harder, since default behavior will stiil just use the Windows MBR.