how to boot debian from grub on dual boot system

When I first installed Debian on this dual boot laptop and restarted it 
I got a message about not being able to load a kernel and then a grub 
prompt. I received some advice which I don't remember. Before I applied 
any of that advice I rebooted and it went straight to linux.

Last night my laptop shut down for some reason (power?). I made several 
unsuccessful attempts to reboot. Then I made an unknown key mistake and 
it booted to Windows. I then restarted from Windows. This time it 
correctly booted to the default linux.

Besides this when the printer on my desktop gets reset and I can't get 
it to print, booting to Windows and printing a page and rebooting to 
linux allows me to print from Linux again. I presume these two are not 
related but it's interesting that booting to Windows and back solves 
both of them.

I would love help with both of these.

TIA,

Paul