You asked how long does it take to make an image:
Loaded Question ..
It depends on how big the "engine" is in your computer, it depends upon how "big" the operating system and all installed programs are, it depends in part what "tool" you use to create the image, it depends in part onto what media the image is being copied to and in terms of "backup" just what kind of "backup" you are making.
Having said that ... lets define "backup"
There are three broad "backup" types and each has its place:
#1: Windows "System Restore": (this is an internal Windows function)
This one takes a "snapshot" of certain key system parameters and can offer at times a "one click undo".
It is somewhat limited in nature.
#2: Windows Backup and Restore: (this is also an internal Windows function but its "completeness" is dependent somewhat on which version of Windows you have)
Windows has the capacity to create a system image,
A system image is a complete compressed image of the complete operation system, it settings all installed software. The whole thing compressed as it is at the moment in time that the image was created.
That imaging process from within Windows can be automated so that it occurs with whatever frequency the user desires.
It can be set to "record" the image onto a DVD(s), external drive or preferably a second internal hard drive.
If a second internal drive is installed the backup will happen at the scheduled time as a background process.
On a computer with a reasonably powerful processer (I5, I7) you won't even know it is happening.
I have my laptop set up to make a new disc image and write it to a second internal hard drive once per month.
One New Image Every Month.
#3: Windows also offers the ability to make an incremental file backup at what ever frequency you and your needs require.
I have my laptop set up to make a incremental file backup every day.
What is a incremental File Backup ?
It is the accumulated differences in a file from the last change to the present.
Someone mentioned a "image" getting old or stale.
Well, the state of your computer is the some total of: LAST SYSTEM IMAGE + The last incremental file backup.
If you are a writer, you may wish for your incremental file backups to occur ... every 15 minutes ...
If a total C drive failure were to happen, the purchase of a new hard drive loaded with the last (1st day of the month ?) system image and that being "brought up to date" with the contents of the last incremental image means that machine is up and running just as it was before the failure with no more than 15 minutes loss of data.
Now most people have no need for that frequent of a incremental backup but ... the addition of a second drive allows the entire process to happen without any though or intervention of the user.
If you save on your C drive and you lose your C drive then you have lost all your backups including your factory recovery partition.
System Model Aspire 5733
System Type x64-based PC
Processor Intel(R) Core(TM) i3 CPU M 370 @ 2.40GHz, 2399 Mhz, 2 Core(s), 4 Logical Processor(s)
BIOS Version/Date Acer V1.02, 4/20/2011
SMBIOS Version 2.6
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume2
Locale United States
Hardware Abstraction Layer Version = "6.1.7601.17514"
Time Zone Central Daylight Time
Installed Physical Memory (RAM) 4.00 GB
Total Physical Memory 3.68 GB
Available Physical Memory 263 MB
Total Virtual Memory 7.35 GB
Available Virtual Memory 2.11 GB
Page File Space 3.68 GB
Page File C:\pagefile.sys
The reason I am getting a new computer. My internal hard drive is 500 GB with 282 GB free. But everything except programs & music is saved on my western Digital drive with music backed up to the Western Digital drive. Then all of that is backed up via MS OneDrive.
It is tough to find a laptop that can hold a second drive.
An external works but you have to remember to hook up external to make the backups.