I'd drafted the following just before hazel's last post was uploaded

"I have just managed to load Precise Pangolin as a Guest, but have not been able to open the Wi-Fi connection, as the system requires my user password.

So it seems to me that at least the PP installation is pretty well intact, but is looking for a user password in the QQ set of files. Unfortunately, one or more of these has become corrupted – which is why, when I select the QQ option on the screen, it never loads, but only cycles endlessly through the promise to load in 5 – 4 – 3 – 2 – 1 seconds. "

I'll try to download a bootable Linux image and put it on a memory stick. I think I can manage the second step suggested, but the third sounds a little daunting!

The point of reinstalling GRUB is that you want to get access to your more recent installation of Ubuntu, which doesn't seem to be bootable at present. Also you have been given an unnecessarily complicated boot setup, so why not simplify it?

But don't take my word for it. I'm sure the other people on this thread can tell you whether this is a good way to proceed or not.

The above entry is a Grub Legacy entry and would be on some unknown partition trying to chainload from the boot sector the boot files on sda2. Grub Legacy numbers both drives and partitions from zero unlike Grub2 which numbers drives from zero and partitions from 1.

The above entry is on an unknown partition point to the sda3 boot sector.

Not sure what you're talking about here. I was referring to post 10 (had a typo in my post saying 9) asking you to check the version of Grub if it showed when booting.

I thought your local repair shop might have changed the bootloader but since all you asked them to do was clone there would be no reason to do that.

I would suggest that you follow the instructions from Hazel in post 15. If you are able to create a bootable USB with Ubuntu on it and don't feel you can follow these steps, go to the site at the link below while booted into the Ubuntu USB and download and install boot repair. Use the 2nd option (use the ppa) and select the Create BootINfo Summary option to run and post the link you get when it completes. Do NOT try to make any repairs. This will not fix anything but posting the link from the script will give a lot of details and someone should be able to help.

https://help.ubuntu.com/community/Boot-Repair

Did you try

Except that it seems to be /dev/sda2 you need to mount to get at your Precise Pangolin system, not /dev/sda1! I was unaware that GRUB-legacy numbered partitions differently from GRUB2.

You can always check which Ubuntu system you have actually mounted by listing the contents of its /etc/os-release file.

Yes, it was more logical. Either count both from zero or both from 1.

The problem with the chainloader entries is that it tells which drive/partition it is trying to chainload to but not which drive/partition which Grub is on to chainload from. Maybe a separate boot partition?

I think that to actually get a comprehensive solution boot repair output will be needed.