I followed these instructions to try to upgrade Mint 16 to Mint 17:
http://www.tecmint.com/upgrade-linux...linux-mint-17/

When I tried sudo apt-get update, followed by sudo apt-get dist-upgrade, this is an excerpt of the output I get, right after it tries to start downloading the packages and installing:

Do you want to continue [Y/n]? y
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_TIME = "en_US.UTF-8",
LC_MONETARY = "en_US.UTF-8",
LC_ADDRESS = "en_US.UTF-8",
LC_TELEPHONE = "en_US.UTF-8",
LC_NAME = "en_US.UTF-8",
LC_MEASUREMENT = "en_US.UTF-8",
LC_IDENTIFICATION = "en_US.UTF-8",
LC_NUMERIC = "en_US.UTF-8",
LC_PAPER = "en_US.UTF-8",
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Can't exec "locale": No such file or directory at /usr/share/perl5/Debconf/Encoding.pm line 16.
Use of uninitialized value $Debconf::Encoding::charmap in scalar chomp at /usr/share/perl5/Debconf/Encoding.pm line 17.
Extracting templates from packages: 100%
Preconfiguring packages ...
Can't exec "/tmp/sysv-rc.config.288651": Permission denied at /usr/share/perl/5.14/IPC/Open3.pm line 186.
open2: exec of /tmp/sysv-rc.config.288651 configure 2.88dsf-41ubuntu3 failed at /usr/share/perl5/Debconf/ConfModule.pm line 59
dpkg: warning: 'ldconfig' not found in PATH or not executable
dpkg: error: 1 expected program not found in PATH or not executable
Note: root's PATH should usually contain /usr/local/sbin, /usr/sbin and /sbin
E: Sub-process /usr/bin/dpkg returned an error code (2)

Things crash, and I'm left at command prompt.
All attempts to reset or reload locales get a variation of this error:
sudo dpkg-reconfigure locales
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LC_PAPER = "en_US.UTF-8",
LC_ADDRESS = "en_US.UTF-8",
LC_MONETARY = "en_US.UTF-8",
LC_NUMERIC = "en_US.UTF-8",
LC_TELEPHONE = "en_US.UTF-8",
LC_IDENTIFICATION = "en_US.UTF-8",
LC_MEASUREMENT = "en_US.UTF-8",
LC_TIME = "en_US.UTF-8",
LC_NAME = "en_US.UTF-8",
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Can't exec "locale": No such file or directory at /usr/share/perl5/Debconf/Encoding.pm line 16.
Use of uninitialized value $Debconf::Encoding::charmap in scalar chomp at /usr/share/perl5/Debconf/Encoding.pm line 17.
Generating locales...
en_AG.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_AU.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_BW.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_CA.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_DK.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_GB.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_HK.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_IE.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_IN.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_NG.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_NZ.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_PH.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_SG.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_US.ISO-8859-1... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_US.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_ZA.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_ZM.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
en_ZW.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
es_GT.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
hu_HU.ISO-8859-2... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
hu_HU.UTF-8... /usr/sbin/locale-gen: line 236: localedef: command not found
failed
Generation complete.

I've Googled for solutions for this situation. All solutions fail.

I hope there's an alternative to just creating a separate partition for /home and then installing 17 from installation dvd or usb

If you look at the site below, you will see thr pros and cons of upgrading mint, more cons than pros.

http://community.linuxmint.com/tutorial/view/2

The most obvious thing in your post is the error about locale not set. I don't know how to do that in Mint but you might start by doing an online search with that message.

>>> If you look at the site below, you will see thr pros and cons of upgrading mint, more cons than pros.

http://community.linuxmint.com/tutorial/view/2

Yes, I was already quite aware of all this, before I tried the update/upgrade method.

>>>The most obvious thing in your post is the error about locale not set. I don't know how to do that in Mint but you might start by doing an online search with that message.

Yes, I've already done that. I think I may have to manually key it up with sudo nano, or find out where Linux Mint stores that info besides the standard places listed.

With respect, my advise is to stop messing about with an upgrade and do a fresh install instead since installing from a DVD only takes about 10 minutes on a fairly old ex XP machine.

Agreed - I posted on this recently when I replaced Mint14 with Mint17.
I didn't need to, but decided to try mintbackup as suggested in the link above as I had seen mention that it doesn't work. Seemed to work, but with some caveats:
- has to be run from the real system, not a liveCD.
- the backup for the software selection, seems to get everything - not just what the user added. Useless to me.

With a separate /home partition the install went like a breeze - using a backup/restore should be likewise.