Well I seem to be not even as expert as an absolute beginner! I tinkered with Ubuntu a few years ago and then got distracted. I had no problems installing it from a USB stick at that time. Now I want to start again, as I have a spare PC. It runs Phoenix Award BIOS. Because the HDD had some nasty errors I reformatted it in Windows 7 (before I decided to try Ubuntu again). This time though, I can't get even get it installed. The PC won't boot from the USB, although the BIOS has 3 options:

USB-HDD
USB-ZIP
USB-CD

Not sure what this means, and motherboard manual (Foxconn) is no help. So I have tried to burn a DVD, but it won't boot from that either (yes I did change the boot in BIOS). I am trying to follow the Ubuntu website instructions, which tell me to download the .iso file for Ubuntu. So far so good, but next the site tells me to right click (in Windows 7) and select the option to burn to DVD. I do not get this option in Windows. The DVD I have burned is not bootable - whatever I do the BIOS always says `bootmgr missing'.

Compared with my previous experience, installation has become vastly more complicated. Or have I misunderstood?