Yes, if that's true, use the recovery option of the install to repair the grub config, but if you just get the word
Grub
by itself on the screen, then more is needed.
For this reason, when I set up a dual boot system, I let windows have the 1st partition on the drive, then put a small /boot partition (enough for 2 kernels & some change) in & make it the active partition. Then I make an extended partition & put logical drives in for /swap, / & whatever else (/home, /usr, /srv ...).
This way, if I want to blow away the dual boot without affecting windows, I make the windows system partition active and delete the /boot partition. It then becomes a single boot system. I boot it once to verify, and then I can start over with a fresh, active /boot. Sounds harder than it is & it's pretty painless.