How to backup your Files
Updated 4/4/2017
Also - Create recovery media for your PC!

See also - The Beginner's Guide to PC Backup from PC Magazine online.
Or see this excellent article from How to Geek website.

Paid Online Backup services
    If you have a large amount of valuable, personal or business files you may need to use a commercial online backup service rather than a free service that limits how many Gigabytes of data you can store without payment. Also remember the adage "You get what you pay for." For a list of Paid online backup companies along with recommendations see this list from Top Ten Reviews -

Create a disk image (Disk Clone)
    This will save all user data as well as your installed operating system. No seperate recovery disk is needed. But you will need a Repair Disk to boot your PC to allow you to access and install the disk image you created earlier to get your PC up and running again.
     If you wish to make disk image backups of your PC's Hard Drive and files I recommend that you use a program such as Acronis True Image or Macrium Reflect (free version available) to make a backup image file that you can keep updated. For this you will, almost certainly, need a USB external hard drive rather than a smaller USB Flash Drive.
     USB external hard drives are now available for less than $100 for a 1 terrabyte drive (more than 1000 gigabytes). See some examples at Amazon.
     Amazon also has Acronis True Image software for a good price if you are partial to that software.

Use Microsoft's free tools
    Microsoft also has tools to create system image backups and system recovery (backup) disks. It is called Windows 7 backup and restore. Access these tools by running sdclt.exe or go to Backup and Restore (Windows 7) in the Control Panel. As with Acronis or Macrium above you will need a hard drive large enough for the image file this program will create (generally at least 100 MB, although the size of the image depends on the amount of data on the Windows partition that is imaged). Don't forget to create the Repair disk since it is necessary to boot your PC and to access and then restore the system image to your PC in case of disaster.

    To learn more about these tools go to this Microsoft page for instructions.

     A system image backup will come in very handy if your PC's hard drive goes belly up or is corrupted by malware or, even worse, your PC is captured by ransomware.
     After replacing the dead drive or reformating your original hard drive you would be able to load the backup drive image from your external hard drive onto the new or reformatted internal hard drive. The backup software will also create a bootable Repair DVD, CD, or flash drive to boot your PC then install the image file onto your PC - keep this disk in a safe place along with your portable hard drive that contains the backup system image!
     The image will install your personal files, programs, and Windows operating system all at once!
     Your PC will be back in running order much faster this way.

     There is an excellent tutorial for creating an image file using Macrium free on How to Geek website. The tutorial explains how to create the backup image and then how to re-install it onto your PC at a later date.
     Note: This How to Geek tutorial's purpose is to backup a PC prior to an upgrade to Windows 10, however the procedure works to save your data, no matter the purpose.

Simple backup to an inexpensive USB Flash Drive or the Cloud
     The easiest and most simple way to make secure backups of your important files is to either save them to a USB Flash Drive or back them up to the Cloud using a free online backup site.
     If the files you wish to backup total less than 15GB (for Google Drive) or 32GB (for an inexpensive Flash Drive) - you can do this without buying a much more expensive external hard drive along with the backup software.

Be sure to copy the original files to the backup disk or drive and not simply the shortcuts to them. Any shortcuts saved will point to nothing when you reload your files to a new hard drive or new OS installation. You will be very disappointed!

Note: Using this simple backup
     If the hard drive in your PC fails it will be necessary to reinstall your Windows operating system along with your programs. Then you can transfer all of your backed-up files from your USB Flash Drive or from the Cloud.

Using a Flash Drive

      My recommendation is that you get the largest and fastest flash drive you can find within your budget.

*For backups, get at least a 16GB drive - 32GB is better.
     A USB 3.0 flash drive is normally faster than the common (and less expensive) USB 2.0. However to be able to take full advantage of the increased speed of the USB 3.0 interface you must also have a USB 3.0 port on your PC.
     Computer makers have started to include USB 3.0 ports on their products only recently - in the past few years or so, mostly in high-end systems. But now you can find USB 3.0 ports even on the most least-expensive new PCs. (Note: USB 3.0 port normally have blue tabs inside. However you may find some (very few) are simply marked SS, for SuperSpeed USB.)

     Sandisk, Kingston, and Lexar are generally the three best and most reliable brands for USB flash drives. PNY and Corsair are also quite good. Most other brands are generally cheaper knockoffs.

     When plugging a Flash Drive into your PC the Autoplay window will open. If you plan to manually drag your files to the Flash Drive to save them, simply choose Open folder to view files. Then you can drag all the files you wish to save from your Libraries folder into that window to save them to the Flash Drive.
     Nearly every time you drag files to the window of a removable drive (flash drive or portable hard drive) a file transfer dialog will open to show that the file is being copied to another device. However, if the size of the file is small the file transfer (copy) dialog may not even show, the file will just appear in the new device's window.

*To make your flash drive last as long as possible be sure to remove it from the PC when not actually using it.
     Remove the drive by using the Safely Remove Hardware and/ or Eject Media applet located in the taskbar (see below). Be sure the drive chosen is the one you wish to eject. Occasionally the USB drives will show more than one device attached. (Other removable devices are also connected by USB.)
     Be sure of the drive letter when ejecting the drive. (The drive letter will be shown in the window when it opens after inserting the drive. Be sure to choose the correct drive you wish to remove.)
     Another way to safely remove a USB drive is to choose Computer or This PC (in Windows 10) from the Start Menu and then right-click the drive you wish to remove then choose Eject from the context menu.

This icon is the Safely Remove/Eject media icon that will be present in the Windows 10 Taskbar when you insert a USB Flash Drive or plug in a portable hard drive connected by USB.
     Click it to safely remove your USB device.

     The best use of a USB flash drive is for backup only - not for primary storage. Make backups of all important data (files, pictures, music, etc.). You can always update your backup whenever you add new files to your PC.
     Leave copies of all data on your PC unless you must remove it for security reasons. That way if disaster strikes, your PC's hard disk fails or Windows must be reinstalled, your data can be loaded back on your PC's new hard drive or even onto a new PC.

Online backup - to the Cloud
(If you have a fast internet connection - DSL or Cable)

     Another way to back up your important data is to get a free account with an online backup site such as Dropbox, Google Drive or Microsoft Onedrive (formerly Skydrive). You get up to 2GB free backup from Dropbox. Google is still offering 15GB with Google Drive. But Microsoft, who had also previously offered 15GB free storage with Onedrive, will now limit their free offer to 5GB.
     Even so, if you don't go over the limits you'll never need to pay for their services.

     To get the most from Dropbox or Onedrive you should install their software when you sign up.
     For Dropbox simply go to their site and sign up then follow the directions - choose the free option!
     Both Windows 8 and 10 include Onedrive built in. But if you are running Windows 7 install the Onedrive desktop software after signing up.
     Both services' software will place an icon in the taskbar to access the settings and a folder in the Explorer window to which you can save your files. (See below)

     The online files are protected by username and password and 256bit encryption so they should be safe from prying eyes.
    Create a good password for these services. A good password has at least eight characters containing both letters and numbers and one capital letter.
     The username for Dropbox will be your email address.
     For Onedrive you can use your existing Microsoft account - if you have one. If not simply create a free Hotmail or Live account with Microsoft. An added benefit is that you get a free online email account (with also along with a Onedrive online space. Google Drive will also give you a free Gmail account.

     Be aware that if you install the Dropbox and/or Onedrive software on your PC the startup time will be increased a bit since the online files must be synced with the ones on your PC when you boot your computer. However this is not a bad tradeoff since your files will always be saved the moment you create them if you save them to the folder created by the (Dropbox or Onedrive) program.

     After installing the software (either Dropbox or Onedrive) look for their folders in the Favorites section of any File Explorer window.

Be sure you have recovery media for your PC!

    If you have a PC that has Windows 7 or an earlier operating system installed you likely already have recovery media you can use to re-install the operating system software in the event you must replace your PC's hard drive. Always keep these disks where you can find them so they'll be available if and when you need them!

    However, if your PC came with Windows 8 or 10 installed it is unlikely that your PC shipped with recovery media.
    Thankfully, there is a relatively easy operation to create the recovery disks on DVDs or a USB Flash drive. It is prudent to use high quality disks to create this media. Multiple DVD-R disks or any good quality Flash drive (16GB or 32GB) will do.
Note: I recommend, before you purchase a Flash Drive to use for a recovery disk, that you run the recovery program to see how large a flash drive you will need. See below "How to do it".

Haven't created your recovery media yet?
    If you have not created a full disk image of your PC's hard drive you should create a recovery disk.
    If it has been a while since you bought your new Windows 8 or 10 PC and you still haven't created your recovery disks I recommend you put this on the top of your list of things to do. If you wait until your PC's hard drive fails then it may be too late. You may need to bring your computer to a PC repair person and pay to have him or her re-install Windows 8 or 10 back onto your computer.

How to do it

    If you have had your Windows 8 or 10 PC for a while and wish to create your recovery media do this:

    *For Windows 8 - In the Start Screen type Recovery or if you have a third-party Start Menu installed type it into the Search Box in the Start Menu.

    *For Windows 10 - Click the Search (magnifying glass) icon in the taskbar then type Recovery, then press enter.
    *Choose Recovery Media Creation. (Under Apps in Win 10)

    *Get good quality DVD-R disks (probably at least 4 to 8 of them) or a good quality USB Flash Drive, 16GB size or possibly 32GB - check first by running the Recovery Media Creation program before you buy the flash drive. The size of the flash drive needed depends on the size of the recovery partition on your PC's hard drive. The size can vary with each PC make.
Note: Any data on a flash drive can be altered or deleted. Do not use your Recovery Flash Drive for any other purpose!

    *Insert the disks or flash drive when the Recovery program asks for them then follow the directions.

    *You may use the program to create only one copy of the recovery media.

    The creation process is nearly automatic assuming the recovery partition on your hard drive has been left in place and/or there is no damage or disk errors on your hard drive. That's why it's a good idea to create your recovery media soon after acquiring your Windows 8 or 10 computer.

Important Notes:
    At the end of the Recovery disk creation process the Recovery program will normally state that since you have created your disaster recovery disk(s) you can now delete the Recovery Partition on your hard drive.
    I recommend that you keep your Recovery Partition on your hard drive - don't remove or delete it!
    If you were to have a problem (such as a severe PC virus) that required re-installation of the Windows OS you could use the Recovery Partition on your hard drive to either Refresh or Reset your PC. This process would normally not be possible if the Recovery Partition were not left intact on your hard drive.
    For more information concerning the Refresh and Reset options of Windows 8 and Windows 10 see my page
Refresh or Reset your new Windows PC.

Be advised
    Realize that Recovery media is not the same as a backup! Recovery Media allows you to get your PC going again after a disaster (a crashed hard drive) but does not save any of your personal data for later re-installation. You will need to create a separate plan to backup and save your personal files.

Final Tip!
Don't move your laptop PC while it's running!
    This information applies equally to both desktop PCs and laptop PCs. However laptop PCs are inherently more susceptable to disk damage from bumps, drops, or mishandling since desktops are unlikely to be moved when they are running. It's always a great idea to turn off your laptop (or close the lid to put it to sleep) first if you must move it. Be sure that all disk activity has stopped before you move it!