Help installing Mint 17 in place of Mint 15 on dual boot with windows7
 

A short while ago I installed Linux Mint 15 as dual boot with windows 7 on my laptop, but now I am trying to install Mint 17 over the top of 15, but I am very confused and don't understand what to do after I choose "Other Option" during the installation. I clicked on the relevant drive which had 15 on it, but it tells me "no root file system defined". Can someone tell me exactly what I need to do to install Mint 17 in place of Mint 15. Each time I press "Install" it throws up messages, and I have no idea when any of it means and what options to choose in the drop-down boxes. Some step by step instructions would be helpful. I found it so easy to install the Mint 15, so I was surprised to encounter complications when I wanted to replace it with 17.

When you click on the relevant partition in the main window, you then need to click the Change tab below to get an Edit partition windows where you can select a Mount point which should be the root symbol: /, That is why you are getting the no root filesystem defined error, then click the format box and make sure you get the correct partition.

Boot device dropdown box
 

This info was very helpful, but I have one more question. What should be showing in the dropdown box underneath which says 'boot device'?

Do you mean the Device for bootloader installation? The default is usually /dev/sda which means the hard drive which is the primary drive on the computer, to its master boot record. If you have only one hard drive that would be what you would nead, if you are now using the Mint 15 Grub bootloader to boot both it and windows 7. The Mint 17 bootloader will replace the Mint 15.

Thank You! Most helpful. I have just been worrying in case I installed anything in the wrong place and caused my windows 7 not to boot. No-one seems to like windows 8 much and I'm just discovering that Linux is very useful. My laptop speakers would not work with windows 7 and I couldn't find drivers to make them work anywhere, so I tried the Linux Mint and they work beautifully! so now I use the Mint for media and the windows for MS Office! The best of both worlds! Fantastic! I've just started installing Linux for friends of mine who can't afford new PCs. Their old PCs get a new lease of life with Linux - and I don't have to spend so much time on the security and maintenance.