Essential Repartition Too Tricky for this Newb

[Bucky Ball]

I don't have a functioning CD drive. That's why I put the GParted iso on a usb.

Should download another copy of Ubuntu onto an external drive?

No. Scrap Gparted on the USB, download the Ubuntu ISO and put that on instead. Boot from that and get to the desktop ...

[dialectical1]

Ok, I finally have the Ubuntu ISO mounted, but not a clue how to boot it.

I have very very limited space on my system, so if I were to (re?)install from the iso (as per this), it may be very risky. Also, I likely don't have enough space on my drive to install startup disk creator, if this is the general procedure you want me to follow.

Currently, I have 578 MB free, subject to go to nil if firefox acts up. (If my system freezes with no space, I can't even log onto my desktop.)

[Bucky Ball]

Boot the machine and hit whatever key takes you to the BIOS. Make sure you are booting from the device with Ubuntu on (CD/USB).

That should get you to a desktop. Launch gparted.

If you do reinstall, click 'Something Else' when you get to the partitioning stage and do it manually. You will see the already existing partitions quite clearly. Just don't touch 'em. Make an extended partition in the free space then put Ubuntu on logical partitions inside that:

/ = root partition; 15Gb fine;
/swap = swap; 2Gb fine.

Easy. If you want to reassure yourself, check that the existing partitions are set to 'Do Not Use' and they are not ticked to format.

You should always backup data you don't want to lose in case things go pear-shaped.

[dialectical1]

I keep fiddling, yet the new option is not showing up in the BIOS menu.

Also, how do I save the backup to the external drive rather than somewhere in root?

[HiImTye]

remember to swapoff before you start making changes to any hard drive with a swap partition.

[Bucky Ball]

I keep fiddling, yet the new option is not showing up in the BIOS menu.

Use arrows to get to the Boot tab in BIOS. Where this is can vary depending on BIOS, but you need to set the CD/Optical drive as your first boot device and restart. If there is a CD in it that should boot before the hard drive. There will be no indication of what's in the device. BIOS sees it as just an optical boot device.

Also, how do I save the backup to the external drive rather than somewhere in root?

Boot from a livecd and get to the desktop. Plug in the external drive. Backup the files.

[dialectical1]

There's a number of even older versions of my ancient kernel, restore mode, as well as Windows (which actually wouldn't work, as I gutted its system files). I don't see any new options ... is it ok if it's in a subfolder of the external drive, or should it be in the main folder?

Boot from a livecd and get to the desktop. Plug in the external drive. Backup the files.

Following this tutorial? Or some other process?

[dialectical1]

Okay, apparently I needed to enter the boot device selection menu (or something like that), but it's still not working. The external drive has only been used with a unpartitioned Windows machine (and mine), yet it fails to boot the Ubuntu .iso due to a "invalid partition table". No clue where/why it's getting that. Any ideas?

[Bucky Ball]

You're trying to install the ISO from a hard drive? Never heard of that but may be possible.

Why are you not installing from a USB or disk?

[dialectical1]

An external storage device, rather. There's not enough space on the thumb drive to store the iso. And again, my cd drive doesn't work.