Apologies for a long post - it may be of interest to other Newbies. It isn't really a "Question".
I have just (on Friday last) wrecked an installation of Elyssa by opening the root partition simultaneously in two places - one by opening my /user folder (which is /theo) and then going backwards via /home to /, and the other by opening Filesystem in "Computer" - I'm not quite sure what my disastrous action was, but the end result was that opening /home showed /Lost & Found and /theo (my user folder) and then opening /theo showed empty - at first in only one of those places, then in both!
Since then, that installation ("Elyssa4" in my setup) has refused to boot - recovery mode made a few repairs, but with no improvement. Currently I am using "Elyssa3" but this system hardly ever boots (goes to BusyBox) and I had almost abandoned it. Great surprise & relief when it booted this morning!
In the meantime I've learned a lot. Some time ago in an exchange of posts about other matters someone (I think it was Fred) recommended Puppy Linux, and I downloaded that and made an installation disk, but had never tried it. Yesterday, with no other access to my machine, I decided to try - it is really useful, if a bit difficult to understand at first. No rival to Mint, but very rapid to install and get going.
I found that I could access my partitions and transfer files, so first I examined /home of Elyssa4, found it readable, then copied the 4 key files for backup - .mozilla (for Firefox settings) and .mozilla-thunderbird for mail archives, profile and address book, also Tomboy and Tomboy.log. I created a folder for them in one of my Backup partitions, and also copied them to another location - belt & braces! All the rest of my data are on other disks, separate from the working system.
Today, as soon as my old Elyssa3 booted, I parked its 4 key files and copied/pasted in the versions of them saved via Puppy from the defunct Elyssa4. Now it's up to date. The backup process will have to be repeated before it is closed - it may never boot again!
Of course I am anxious to install a fresh system - first attempt produced an error - the disk has been used about 6 or 7 times - so I decided to do a fresh download on my laptop under W-XP-Pro - that ultimately turned out to have an incorrect md5sum after wasting a lot of time. I couldn't see how to check it under Windows or Puppy. There was a copy of my original download in the laptop, by way of backup, and I was going to use that until I got this successful boot giving access to my PC discs.
Now however I have cleaned the lenses of my CD-ROM and DVD-RW drives and burned a fresh installation disc from my original download of the LinuxMint-5-r1.iso file, having checked its md5sum - still correct. I hope for a successful installation of what will be Elyssa5 - with 104 updates to go, as well as various items of software to add. I note however that Firefox extensions get transferred forward by copying .mozilla.
One interesting fact is that all the files in my /theo folder in Elyssa4 were visible using Puppy Linux, but it again shows as empty using Elyssa3. I had to mount it by command - it didn't even appear in "Computer". I shall not overwrite it for the time being - I still have spare partitions. For interest, I shall investigate whether it still appears under Puppy.