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It's tempting to backup to a separate partition because it's somewhat like another disk. The problem is that it's not. You could be risking your data.

I am going to do a clean install of Windows 7 x64 to hopefully fix some errors, which means that I need to back up my files. The problem is that I don't quite have the means to back up my hard drive. Can I simply create a new partition on my existing drive (1TB), copy my files to that, and then perform a clean install on the existing Windows partition? Afterward, I would transfer the files back and delete the "backup" partition. Would that work or am I heading in the wrong direction?

Yes, but...

There are risks. In fact, you're running a huge risk without even doing a thing.

Because people often ask if backing up to a separate partition is a valid backup approach, let's examine the scenario in more detail.

You're Just Managing Data

What you describe isn't really backing up. You're just moving some files over here so that you can erase that stuff over there.

"Backing up one partition onto another where both partitions are on the same hard disk is, at best, only half of the solution, and, at worst, a disaster waiting to happen."

And, as far as that goes, it's a fine, fine approach. In fact, I'm sure that I've done it myself at some point in the past. It's a fast way to copy some files around so you can wipe out what's on the primary partition and then copy the files back later.

But I'm not going to call it a backup and I suggest that you not think of it that way either.

For how you're using it, it's a fine approach.


You're Not Backing Up

This statement concerns me more than anything else:

"I don't quite have the means to back up my hard drive."

So, to put it perhaps too bluntly, you're willing to have everything on that hard drive disappear forever if there is a catastrophic failure?

If so, fantastic. You're good to go.

But I suspect that that's not an acceptable scenario for you. As such, I strongly urge you to figure out some way to do real backups that will cover your assets should there ever be a need.

A Different Partition is Still The Same Disk

Backing up one partition onto another where both partitions are on the same hard disk is, at best, only half a solution; at worst, it's a disaster waiting to happen.

It's very simple really: if the hard disk dies, all of the partitions on it go with it. If you've been putting the backups of partition A onto partition B on the same hard drive, then they both disappear at once.

It's like having no backups at all.

Backups on that second partition may be useful for some kinds of errors. Say that you deleted a file that you didn't mean to or that a bad sector crops up on partition A - the backup from partition B would still be there and available to copy back.

But that completely ignores the more disastrous scenario of a catastrophic failure of the entire hard drive and the loss of everything on it.

In case I've not been clear: don't do it.


Backup, and Backup Somewhere Else

So, find a way to backup. That's a given.

But when you do so, backup in such a way that you're as isolated from the events that might cause you to need the backup in the first place.

  • Backup to a second drive, preferably external, to separate the backup from the original hard disk.

  • Backup to a second drive that you then disconnect, to separate the backup from software "going rogue" on your machine and deleting or corrupting data on all connected drives.

  • Backup to a second drive that you then disconnect and take elsewhere, to separate the backup from your home in case it's robbed or goes up in flames.

Online backups are a possible solution as well, though they are less capable of handling complete system images or other large backups.

In practice, simply doing only the first - backing up to a second external drive - will get you 99% coverage for most of the problems that you're likely to encounter.

Article C4800 - April 20, 2011 « »

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Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

April 26, 2011 12:50 PM

Hi Leo, I totally agree with your comments on system and data backups. However I am going one step further by backing up all my important information on two separate external hard dives. Yes it is more work but here is the reason why I do it. In the last twelve month three hard drives died on me, no warning one day they where working the next day they where dead. The latest casualty was one of my backup drives with 250 GB of information on it. You may think that this is overkill but I sleep a lot better knowing no matter what happens I have a spare backup.

Jim de Graff
April 26, 2011 3:37 PM

I presume the user was going to use a partitioning tool such as gparted to shrink the existing partition in order to create the new partition (as opposed to creating a new partition in already existing unused space). The standard recommendation before repartitioning like that is to do a full backup first. This puts the user in a bit of a bind because in order to do the backup he/she must first repartition. Spend a few bucks, buy an external drive, then do a proper backup. When I buy my drives I do so in pairs. After doing a backup to one external I immediately do a sync to the second external. Drives occasionally fail and I want my backups to be as secure as I can reasonably make them.

Barcillo Barsiniestro
April 26, 2011 8:23 PM

I use a similar aproach for regular reinstalls and also to separate the more important data. I have 3 partitions in my 1TB HDD.
C: OS, Programs, programs data and garbage. I don't backup this partition, except for the desktop and selected files from C:\Users (I don't use My Documents).
D: All my Data, I backup this one every week to a 500GB external drive I disconect and keep in a diferent room in my house. I'll soon run out of backup space if I don't buy a bigger external HDD..
E: Expendable files, Files waiting to be backedup to DVD and a copy of some of C program data. I don't backup anything from this drive.
If anything goes wrong with my SOFTWARE, I copy selected files from C: to E: via BAT file (or use the latest copy I have there) format C: reinstall and I am ready to go in less than an hour (I may spend some more time tuning up later, but I least I can work) with no need to restore data files.
If things go wrong with the hardware, I fall back to the external HDD backup.

In addition to the D: external HDD backup, I also keep 150+ DVD backups of all my data, these are stored in a secure location away from my house. This was my only backup system before, it's very time consuming, and a restore takes more than a month. I know it, since I got my home burglarized a couple of years ago by some G-men sent by a crazy ex-girlfriend who works with my country's goverment, and had BOTH my PC and attached backup external disk stolen. I had to restore all my 500+ GB Data by copy-paste, unzip, and then weed out duplicates and organize it again. I lost some data that was in the stolen backup disk but not in the DVDs so now I continue with the DVD backup even if it's a pain.
I got demanded from the Crazy ex a coupple of days after the robery, but she didn't expect the DVD backups. Without them, I would have gone to Jail.

By the way, my new HDD died a couple of months after the manual restore (there where massive blackouts in my country for some months), before I was able to buy a new external HDD, so I had to AGAIN spend a month restoring from DVDs.

I also keep some very important files backedup in DVDs with friends outside my country and/or online under fake IDs (don't want another atack of the crazy ex G-woman).

As soon as I can, I plan to buy a larger external HDD and do as Leo recomends (image and backup everythng), but untill I can afford it, I think I can live with what I have now (cost - benefit). Leo's recomendation is great under optimal conditions, but sometimes you have to priorize and personalize your backup/restore strategy.

Citing Leo "It all depends".

April 26, 2011 11:54 PM

I had my vital data such as family pictures backed up on an external hard drive. Guess what: it crashed. With Recuva I could recover half of them (about 6,000), the other half was gone. But that was not over yet: I could not open about half of the recovered ones anymore, though they looked perfectly normal on the drive (name, extension, volume, date). I tried every possible free graphic prog, but to no avail. Not much of trust in drives whatsoever anymore.

I actually had a similar experience, except it was my CD collection. I now have *two* external drives and automatically backup one to the other. That way either can die.
Mark J
April 27, 2011 12:09 AM

Unfortunately you probably didn't have your data backed up to an external hard drive. That hard drive was probably your only copy. If it were backed up, you would still have the original. A back up means having 2 or copies. . I have an external disk back up of my computer, another external disk back up of all my data. A Dropbox folder with my most important data, and Backblaze (a commercial cloud backup solution). I can't personally vouch for Backblaze because I haven't had to use it yet, but it's inexpensive and I've heard good things about it. Carbonite also has good recommendations but I've never tried it.

April 27, 2011 4:11 AM

Thanks, Mark, for the comment, but I had my pictures backup up to my external hard drive (which you can read in the first sentence). I just wanted to state out that even this medium is not safe enough. But it's not only photo's I send to my external one. Video's, music and about 45,000 pictures of paintings, in total are we talking about 500 GB. I am even planning to put everything I have on my external drive (cd's and dvd's) which might increase the volume to 1 TB. I don't really think in my case the cloud is the best answer! But there's no alternative, I'll have to go on living in fear...

Mark J
April 27, 2011 4:54 AM

Biogaraph, I can only suggest having more than 1 backup. As for Backblaze, I have about 1.5 TB backed up their server for $5.00 a month. I don't even have to think about it. (It took over a month to complete the backup). But it's just one of my backups. Or you can bring a copy of your backup to a friend or relative's house. External HDs are cheap. We used to have to bring a a back disk home from work every night and bring the older one in the next day.

July 3, 2012 6:18 PM

Sad story: Seagate external drive still in the box. too late to use it now - "partitioned" D drive got infected and not sure it will ever be clean (HP doesn't send Windows recovery disks - they partition). so glad I don't depend on computer for a living - would drive me crazy.

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