Sayeh Ebrahimi wrote:
Haven't installed on Thinkpad specifically, but in general you should not experience any problem if you pay attention to these points:
1. It is much better to have M$ Win and then install Debian.
2. While installing do not trust the installer suggestion for automatic/guided install; and choose manual install option.
3. Finally, in the last step, the installer will ask you about GRUB boot loader. Just be careful and read the text in order to make sure whether it has detected your M$ Win OS or not; based on that guide, choose whether to install GRUB on the MBR of your first partition or not.
-- Sincerely yours Amir H. Moin