The best option is to get a new hard drive. You can find one for $100.

Then just connect your old drive to the PC with a USB to SATA adapter and copy any files you need.

With the extra drive there is no risk to your data from the install as long as you DON'T CONNECT THE OLD DRIVE DURING THE INSTALL PROCESS, since you could conceivably choose the wrong install disk. If it's not plugged in then you can't choose it

If you have 1 backup, you have no backups; If you have two backups you have one backup.

Just make a backup of your data, it's the easiest way. Can it be done without a backup? Yes, but it's complicated and error prone. Better go the safe route.

OP, please don't let the other users scare you off. I've installed Linux dozens of times on dozens of different computers and have never once lost data while doing it, not unless I explicitly choose the option installer telling it there was nothing I wanted to keep (which is labelled "DANGER - YOU WILL LOSE DATA" in red letters). Linux Mint installer has an option to let you keep your existing OS and install Linux alongside it in a "dual-boot" configuration. This means that when you install, you permanently set aside a portion of the capacity of your boot disk (hard drive, SSD etc.) for use by Linux. The total capacity of your Windows partition will shrink by that much and Linux will live in a new partition in that space (e.g. if you have a 1TB SSD and set aside 250GB for Linux, from then on Windows will start seeing your C: drive as being 750GB large and Linux will have a brand new 250GB volume as its equivalent of the C drive). You can change how much space each OS has down the line, but it's really annoying and requires you to boot off a flash drive and not be able to use your computer for several hours while it rearranges its data.

After that, each time you turn your computer on, you'll be asked whether you want to boot into Windows or Linux. (This will come in very handy if Linux borks itself and you need something working to be able to Google for solutions and use your computer as a computer until you can figure out how to fix it. Or if you decide down the road that the Linux way of doing things just gets under your skin and you want to go back to how your computer was before.) While booted into Linux, you'll be able to access all the files on your Windows C: drive as though it were an external drive, but not vice versa. If you want to send files from Linux to Windows, you'll have to boot into Linux and copy them over. Note that from the perspective of any apps you install on either OS, your Windows and Linux partitions are two totally separate computers, so expect to be asked to sign in again.

All that said, having backups is never a bad idea if you can afford it. If you can't, a surefire way to keep Linux installer from erasing your Windows files is to put two SSDs in your machine, one for Windows and one for Linux, and disconnect the Windows one until you've finished installing Linux. This is what I usually do, and as a bonus gives more space for both OSes, although it's by no means necessary.

The most important thing to do is backup your data to an external drive. Unless you are planning on dual booting (much more complicated) you will be wiping out the entire drive that has windows on it when you install Linux.

This guide goes through the whole installation process.

You could dual boot and access your documents from linux by mounting your windows partition. Don't forget to backup your data before you do anything, especially if this is your first time doing this.

What data

Heed the backup data warning.

But if you just want to test mint to see how it feels, you can boot from a USB and install mint on a second usb. That way you are less prone to lose any data should something happen.

Make sure that the second USB is somewhat recent and has minimum 32 Gb for an optimal experience.

Back up your data before hand.

You can use gparted on your mint live session to resize the windows partition to minimal size, leaving the biggest empty space possible. Leave 500mo to the windows partition as a safety net.

Then during the install process :

• choose manual install (not install on a full drive),
• create an ext4 partition for the system (30 to 50 go) with a "/" mount point. It's the system partition.
• create a "swap" partition (size = your computer ram x 2). It's the physical memory partition.
• last create an ext4 partition (all remaining space) with a "/home" mount point. It's the personal data partition.

Once the install completed you will be able to access your windows data from mint.

How much and what data are you looking to keep?

This is slightly unrelated, but I’ve been slowly moving to Linux from windows for a while. I haven’t made the full plunge yet, but here’s my biggest strategy:

Use as many apps on windows as you can on Linux.

I’m using Okular, Ghostwriter, Libreoffice, Cider, etc. every month or so, another app is moved across.

Then, I make the switch and all my apps are there as I’m used to them.

Best way to not lose data is to never delete it. Buying a new hard drive can definitely do that but backing up everything you want is completely fine too.

If you don't want to lose data you have to keep it somewhere. Current hard drive is a good choice.

Someone suggested getting a new disk drive/SSD, which is a good approach if you don't mind a relatively hard cutover. But if you have the space and funds for it, it may be simpler to just get another computer and run Linux on it from the beginning, while also keeping your Windows machine running. Then you can gradually migrate your files and activities to Linux as you go. Once you're not using the Windows machine much any more, just unplug it, don't throw it out. You can then turn it back on if you need something from it.

1. 1. Make a backup. Use the windows backup utility for this, it’s real good. After that, look at what it backed up and make sure it didn’t miss anything.
2. 2. Plan out what you wanna do. There’s a lot of posts in reply to this thread that suggest different ways of doing things. If you plan what you want and investigate how to do it you will fail less.

What do you wanna do?

Your personal files? Back them up onto an external drive in Windows and then copy them into your home directory after installing Linux.

If it's app data also copy it into an external drive and import it into the apps after installing them on Linux. Depending on the app they may have cloud sync options you can use too.

Step 1: "Unlearn" everything you learnt about technology and pcs as a whole and embrace Linux with a open mind.

Step 2: Kill the bad habit (that only Windows gives you) of expect everything to "just werk" and to "solve" all your problems with left clicks. Yes, that is a bad, terrible habit and should not be accepted/be a daily habit for you and no sane user out there.

Step 3: Nah, you'll lose everything -- just YOLO it.