I just resently cloned my hdd with dual boot windows 10 and Linux Ubuntu using macrium to a smaller ssd. If the HDD is disconnected, the SSD will boot like perfectly, fast, with all the programs like it's just an improved version of my old PC. But if the HDD is plugged in I will boot the grub on the SSD and it will take ages to load windows, and after when I check, the old HDD is listed as the C drive. My theory is that the grub/mbr in the new SSD is still calling for the old windows installation because when the HDD is connected it detects that as C: and the SSD installation as F:.
I don't know what to do because of course I want the OSs on the SSD, but keep the 1 TB HDD for storage.
edit: I already edited the boot order, and I pulled the bios boot menu and selected the SSD for booting, that's why I know the new SSD Grub/Mbr is calling the old installation.