Installing Linux Mint, how to partition disc, mount points, boot flag?

Question

I'm getting used to Linux a bit now, came to it as an XP refugee, and am still firmly a noob. I can google until I'm blue in the face, but I still don't know enough to understand what all the contradictory advice is telling me, or whether its context is applicable to me.

I needed more space on my HD, I'd not used the XP dual boot in a year, Mint 17.2 was out, and I wanted a separate /home partition, so I decided to go for a clean install. I'd done it before, I should be able to do it again. Last time I opted for the automatic process, which used one partition for system and /home.

I made a USB and a DVD of the 17.2 Mint Mate 32bit live distribution. My fairly old MOBO will not boot from USB, whatever I try to tell the BIOS, so DVD it is.

Running from the live CD, I used Gparted to delete all and then create 3 new partitions intended to be /, /home and swap. I was able to set the boot flag in /, but not set mount points. Starting into the installer, the manual HD partitioning option did not allow me to set mount points. Back to Gparted, deleted all partitions. Back into the installer, creating partitions with mount points /, /home and a swap area. But I was not able to set the boot flag on /, which I could do in Gparted. Asked it to install in my / partition.

The rest of the install progressed without error messages. On restart, I get 'error:, no such partition, entering rescue mode ...', and get the grub rescue> prompt.

I would guess that the / partition should have had the boot flag set, though the installer didn't give me an option for setting that.

Also tried making an ext2 partition mount point /boot that I've seen some tutorials suggest, still no joy. Tried making that partition FAT32 in case my BIOS was the problem, but the Mint installer told me to change it back to ext2.

How do I get the right mount points and a bootable system?

(edit) Nah, given up, I let the installer erase the whole disk and do what it wanted. It created one bootable partition for the OS and my home folder, and it works. Yes, I did 'try before I buyed', but you only run into problems with the rebooting process once you've installed and try to boot. The fact that grub rescue would have told me something about how much was working, if I had the experience to know what that was (/edit).