OK I give up, I have spent more than 8 hours trying to get Mint installed on my HD, this has been the most annoying fresh OS install I've been through since the last milenium and frankly I have other things to do.
Just for posterity I will waste 30 more minutes here so as to share the pain and hopefully spare someone from going through it.
Machine : Dell Latitude D630
Had win7 installed on C: & D: was data partition.
Downloaded the ISO then put it on my 16gb USB stick made bootable using Win32 Disk Imager under win7.
Booting from USB without problems I get to Mint desktop & click on Install.
Getting to the "select partition" part of the installer and wanting to keep my D: partition I delete the C: one & create in that free space a /, /boot/, /home and /swap following this handy guide : http://www.linuxbsdos.com/2012/04/25/ma ... nt-debian/
Install goes on without problem until a pop up says Grub fatal error, bootloader cannot be installed. I only have two storage devices : SDA, the internal hard drive on which I want to install Mint and SDB, the USB stick from which the install/LiveOS is running.
It just wont write the bootloader on SDA. Checking the partition table in terminal I see the /boot is attributed to SDB instead of SDA.
I back up my D: and wipe the hell out of the hard drive, reboot then follow the partitioning guide once more to get my clean 4 partitions setup. /boot, /, /home and /swap.
Redo the install, specify " / " for install then wait, all files copied no problem but once again Grub fails writing the bootloader on the MBR (i'm guessing). So i select install mint without bootloader, go to term, check the disks and SDA doesnt have the * under the boot column, only the stick has it.
I install and use Boot Repair sucessfully, reboot without USB I get to grub OS selection ; select Mint and then black screen, I wait 5 or 6 whole minutes then reboot on USB to get on the web & do yet another troubleshooting search in google. Video driver issue? Do some "modeset" editing on the grub commandline to specify intelGMA, then Ctrl X and finally get to a low-res Mint screen with 4 points moving left to right, eternally.
Say to myself "*** it!", i'm getting Ubuntu.
Thanks for listening, the user experience / interface in Mint is very nice but this felt like linux in 1998, not 2012. Maybe there's an issue with booting from USB, maybe another with video drivers, whatever the case people cannot be expected to have to use command lines & partitioning software right from the start of their Linux switchover. The installer should be optimized to let people keep their Windows Data partitions in an easy to use manner. "Keep X:, crush the Windows install partition". The video drivers should be universal, like win7's installation wizard.
I will wait a bit and keep an eye on Mint, disappointed to have wasted so much time. If I wasnt a techie I wouldn't have wasted so much time, at the second bootloader failure I would have simply switched to an other distro. Stupid techie me!